PRESSES
An exact description of all presses used hitherto for lithography would
demand a book that would nearly equal the present one in magnitude. Many
drawings would be necessary, which would increase the cost of this
text-book without adequate benefit, as I have learned that one rarely
can find a mechanician skillful enough to make a machine even when he
has the very best description and a perfect illustration before him. I
advise all who intend to enter lithography to send for a model to Munich
or some other place where the art is being practiced with success. I
myself am willing to furnish exact models for the price of one louis
d'or, which must be remitted with the order.
There is no press as yet that is so perfect for lithography that it
leaves nothing to be desired. The press whose plan I laid before the
Royal Academy of Sciences in Bavaria, which does its own inking-in and
which can be worked by water-power, has not yet been built on a large
scale, so that its value cannot be stated exactly.
I am only too well aware, however, of a grave defect in lithography,
which is that the beauty and even the number of impressions depend
mainly on the skill and the industry of the printers. A good press is
necessary, to be sure; but even with the best a poor workman will
produce nothing but trash, because in this respect lithography is far
more difficult than any other printing-process. I shall not admit that
lithography has made a great step toward the utmost perfection until the
erring work of the human hand has been dispensed with as much as
possible and the printing is done almost entirely by machinery.
Therefore I am determined to realize the ideas I have in this direction
and I shall inform the friends of the art of my success at once.
I
PROPERTIES OF A GOOD PRESS
It has been observed that inscriptions, and particularly drawings, look
better on the stone than on the impression afterward made from the
stone. Partly this may be due to the color of the stone which softens
the picture, because an impression made on yellow paper resembling the
stone color looks very much like the drawing on the stone. But the great
cause of the difference is that the color does not transfer itself to
the paper with the degree of strength and clearness that it possesses on
the stone. That this perfect degree can be attained, none the less,
there are many successful impressions to prove.
If the plate is well designed and well prepared, it will take the color
well and clearly, but the printer may apply too much or too little, the
color may be too hard or too soft, or, even if the stone is properly
inked, the paper may accept color poorly or be too damp or dry. Chiefly,
however, it is the press, according to my experience, that most affects
the quality of an impression.
In most lithographic presses the printing is done by the so-called
scraper. This is a thin slat of hard wood, mostly maple, pear, or
boxwood. It is one line thick on the side intended to do the printing,
and the mechanism of the press forces it on the paper, which is on the
stone and covered with an overlay of waste paper and tensely stretched
leather. This pressure forces the color against the paper along the
whole length of the slat, and only one line broad. The scraper is forced
bit by bit over the entire plate, or it remains motionless and the plate
is drawn underneath it.
It will be observed that this kind of press does not produce the entire
impression vertically and at once as in book-printing, but that it is
successive, as in copper-plate printing, with the difference that the
copper-plate press uses a roller instead of a scraper.
As the scraper must be pressed down with great force (often as much as
sixty and more hundredweight) and must pass over the leather with this
immense pressure, there is a tremendous friction, and despite the fact
that the leather is tensely stretched and lubricated with fat, it is
considerably pulled and strained by the scraper. This pulling and
straining communicates itself to the paper under the leather. Thus all
the lines of the design become a little bit squashed in the direction
described by the scraper. If, however, the leather is very good and very
tensely stretched in the frame, if it is well lubricated, and if the
printing-paper with its underlay is not too wet, the pulling is
inconsiderable so that scripts and drawings in broad effects are not
affected noticeably. Drawings in detail, however, and crayon work
wherein there is hardly a perceptible space between the dots, are so
affected by the slightest displacement that they produce a smeared,
sooty impression.
The scraper has a second fault. If the paper has impurities, it injures
the scraper readily. A groove scratched into the scraper will prevent
any further good impression if the injury is considerable, because it
will leave a streak. The only remedy is to take the scraper off and
plane it, fashioning it accurately to the surface of the stone. I have
tried to remedy this by making a scraper of metal. As this causes even
more friction than wood, I laid a strip of strong paper over the
scraper, which generally was good for three hundred impressions before
it was worn out. Then I merely needed to move it forward a bit; so that
a strip of paper as long as the scraper and six inches wide was
available for some thousands of impressions. The pressure attained with
a metal scraper is greater than with wood; but it has the disadvantage
that it is hard to print a stone whose surface is not absolutely level,
whereas a wooden scraper can be planed to suit any irregularity in the
stone.
The foregoing shows that a good lithographic press must have these two
properties:--
(1) It must not pull or shift the paper in the least.
(2) It must produce a uniform impression without weak spots or streaks.
The other properties it needs in common with other presses, such as:--
(3) It must be powerful enough to produce the necessary pressure.
(4) It must combine the greatest possible speed with this power.
(5) It must be easily operated, to save the workman.
All these qualities combined are not to be found in any press hitherto
applied to lithography.
II
APPLICATION OF BOOK- AND COPPER-PLATE PRESSES TO LITHOGRAPHY
If we consider the peculiarities of book and copper print, we find a
decided difference between them that affects printing importantly.
The letters of book-type are raised, the engraving in copper is
depressed. It is evident that the former requires no such power for
making impressions as the latter. Therefore the presses are so different
that copper plates cannot be printed on a book-press and vice versa.
Now, as the stone combines both the elevated and the depressed
principles, the natural idea would be to combine the fundamental
principles of both presses as nearly as possible for stone-printing. In
book-print, only the types are exposed to the pressure, and in the
average printed sheet these are only one fourth part of the entire
surface. The remaining white space is not affected at all by the press.
In the stone, however, the elevation of any part of a design is so
slight that the entire surface is affected, and consequently a stone
plate offers four times as much resistance. A book-press therefore would
print a stone only if it were arranged for a pressure four times
greater. Now, for a stone of the size of a letter-sheet the power
required to print with one vertical pressure would be five or six
hundred hundredweight, a pressure that could be supported only by a
thick stone laid very exactly on a perfect foundation.
An ordinary copper-plate press increases the pulling of the paper so
much in the case of a stone plate that the impression would be
worthless. This pulling is not caused, as in the case of the scraper,
during the impression itself, as already described, but it is caused
before the impression through the endeavor of the cylinder to force the
plate along under it. Once the stone is under the cylinder, the paper is
not pulled noticeably, because the cylinder glides over the leather much
more gently and with much less friction than the scraper.
This defect might be corrected:--
(_a_) By supporting the cylinder so that it would come down on the stone
only at the point where the print is to begin. But as the stone must be
drawn pretty well forward for convenience in inking, this would demand
that the cylinder be revolved forward and backward again as far as is
needed for the impression, which means a great demand on the strength of
the printers, not to count the loss of time.
(_b_) A second way would be to plane off a piece two inches wide from
the cylinder at the point where the impression is to begin. The stone
could be forced under this space readily, and when the cylinder
revolves, it presses forcibly at once without pulling the paper very
much.
(_c_) The press might be fitted with iron wheels with cog teeth to
engage similar cogs on the cylinder. This would prevent pulling, but the
mechanical work would need to be very accurate.
(_d_) The best arrangement will be the following: Set the upper cylinder
so high that the stone can be brought under it without touching. Then
bring it down with a screw, or better still, with a lever that can be
operated by the foot.
The first figure in the plate showing presses represents about how a
copper-plate press is to be fitted for this work. On the whole, this is
an ordinary copper-plate press, but the upper roller is set with its two
axles or spindles in two iron levers, each of which is fastened to a
piece of wood with iron screws one inch thick. Each of these pieces of
wood is covered with strong sheet iron and can be adjusted higher or
lower with two screws or with underlay of pasteboard. This is necessary
that the press may be adjusted to varying pressures. The two other ends
of the two levers, in which the cylinder sits, can be raised or
lowered, so that the cylinder also can rise or sink. Now two springs or
two weights are so adjusted that the cylinder with the levers always
remains elevated. To force it down on the stone, an iron beam enters
both sides of the press with two pegs so adjusted that when the beam is
turned ninety degrees the levers are depressed at least two inches. As
the cylinder is about in the middle of the two levers, it will thus be
depressed one inch, which suffices to permit the stone to pass under it
freely while it is elevated and gives the greatest pressure when it is
depressed. However, the upper cylinder must not be one inch distant from
the stone, but at the most only one fourth inch, for the remaining space
of three fourths inch is required to provide margin for the elasticity
of the various materials, and also to give margin for increased pressure
whenever demanded.
On one end of the iron beam with the two pegs is an arm or lever which
is joined to a thin stick with a treadle. This tread is so arranged that
it remains elevated of itself. If the pressure is to reach sixty or more
hundredweight, it must not be fastened directly to the treadle, but a
second lever is required which is affixed to the side of the press.
Without going into tedious detail I cannot further describe this press.
Mechanicians will understand me readily and perhaps be able to add many
improvements. My belief is that a copper press so arranged would
diminish all danger of squashing and pulling the impression, furnish
powerful pressure, permit overlays of felt or fine cloth, and make
possible considerable facility and celerity, which is a great advantage,
because impressions always are better if too much time is not lost
between inking and printing.
To safeguard the stone against cracking in such a press, the following
points are to be noted:--
(1) The stone must be ground very true on the under side as well as the
upper.
(2) Both cylinders must be perfectly true, and care is to be taken
particularly that one cylinder is not thin toward the middle and the
other thick, as this would easily crack the stone lengthwise.
The board on which the stone rests must be equally true and uniformly
thick. At the same time it must be very thin, only one half inch thick
at most. It will get very heavily squeezed during the printing, and the
more the impression approaches the centre, the more concave will it
become. The parts farthest from the point of pressure then resist unduly
if the board is thick, and thus become the chief cause of cracking the
stone. If the rollers are very true and the stone is very uniform, it is
almost impossible to crack it if it is passed between the two rollers
without a board underneath. If the board is thin, it is as if it were
not there.
I believe that competent mechanicians can improve the present presses
greatly.
III
LITHOGRAPHIC PRESSES USED HITHERTO
Most owners of lithographic printeries have tried their hands at
inventing presses, but in the end it has always been something based on
the scraper or the cylinder principle. I myself have made more than
twenty designs. Some were very useful and had advantages either in power
or convenience, but generally were handicapped by some defect, so that I
cannot even say with certainty which was the best of them all. So much
depends on the mechanic's execution of one's plans, and a perfect design
can be so spoiled by a workman that it is worthless.
I will, however, recount the best that has been done so far for
lithography.
In Munich two kinds of stone presses are mostly used. They are:--
(1) The lever press, or, as the workmen generally call it because of its
form, the Gallows Press.
(2) The Cylinder or so-called Star Press, the latter term being used
because a star-shaped lever is commonly used instead of a crank to turn
the rollers.
I have tried and found good the following:--
(3) A press with double levers.
(4) A gyrating or sliding press.
I know also--
(5) The roller press used by Herr Andre.
(6) And the press of Herr Steiner in Vienna.
Herr Müller in Karlsruhe and Herr Ackermann in London have a press with
paper cylinders the construction of which is unknown to me.
IV
THE LEVER PRESS
This was the first press that I used with advantage, and it is used
still in Munich in all important establishments for work that demands
speed particularly. It would be an excellent printing-machine in all
respects if it did not have the defect that its power cannot be
increased much more than six hundredweight without forcing the workmen
to undue exertions. Therefore it is no longer available for large plates
or for works that require immense power. It is very good for pen designs
not larger than a letter-sheet, and two workmen, one to ink-in and the
other to print, can produce twelve hundred impressions in a day without
hardship.
The pressure is produced by a lever six to twelve feet long, fastened to
the scraper below and to a spring (an elastic board) above. It is
connected with a tread, and when forced down, presses with the desired
force on the scraper and so on the plate. The board holding the lever
overhead must be partially movable like a spring because the lever
describes a part of a circle on the plate below. Hence the pressure at
the beginning and end of the impression is not so great as in the
middle, and great care in choice of wood and manufacture is demanded to
give the spring board the necessary elasticity and power combined. I
have found a board of young dried pine the best, the dimensions being
six feet long, eight inches wide, and two inches thick, provided that
the fibres all ran lengthwise. It is not always possible to find a good
board at once. Often I have found that the difference between two boards
made a great difference in the effectiveness of two presses otherwise
exactly the same.
The scraper arm consists of two parts, of which the shorter one, to
which the scraper is fastened with a screw, is only one and one quarter
feet long. The other part is as long as the height of the press permits.
The higher a lever press is, the better is it, because then the circular
motion described by the scraper wood approaches a straight line more and
more, so that the press exercises a more uniform pressure during all
stages of the impression and is easier to handle. The second
illustration shows this kind of press in the moment when the impression
has been finished, the printing-frame opened, and the scraper arm swung
back again.
The printing-frame is much like a book-printing frame, and is furnished
inside with a second small frame which holds the paper, being furnished
with small springs or strings. When the frame has been turned over the
stone, the paper must be at least half an inch from the stone to avoid
smutting, which will occur if it touches. The paper must not touch the
stone till pressure is applied, and then only on the spot pressed
downward by the scraper.
As soon as both parts of the scraper arm are in a straight line, so that
they form practically one piece, the scraper wood is pulled down and the
printer draws it toward himself over the printing-frame and the stone
plate. At this time the following is to be observed:--
(1) Both parts of the arm must be so fastened to each other that they
may be bent like a knee, but once they are straight in line, they must
stay in that position. It is well, therefore, so to adjust the parts
that they will not be directly over each other, but rather exceed a
straight line under pressure, and bend a little inward. The position of
the scraper must be considered also. On the whole the following rule
holds good: the point where both parts are united with a nail or a screw
must not be in a perfectly straight line between the point where the
scraper rests and the point where the arm is fastened above, but should
be at least two and a half inches forward of that point. Otherwise the
arm may spring outwards toward the workman and injure him severely. The
third illustration shows the construction of the scraper arm and the
scraper.
(2) The arm must be grasped as low as possible when being drawn toward
one's self, in order to diminish the danger of springing outward.
(3) The workman must press his body tightly to the table of the press to
get proper leverage. Standing free, a man of moderate strength could not
move the scraper at all when the pressure is on, but a man standing in
correct position can do it without difficulty.
(4) Under very heavy pressure the inker-in, who stands on the other side
of the press, can help by pushing.
The scraper is a piece of pear wood as long as the size of the plate
demands. Its height is about four inches, its thickness one inch. The
end that rests on the leather is trimmed down so that it has a thickness
of only one line. This end must be especially true and planed to fit the
stone, also neatly rounded off. It should be so fastened to the arm that
it may be adjusted to the position of the stone. The stone does not
always lie truly horizontal in the press, sometimes because it is not
uniformly thick, sometimes because the underlay is not quite even, and
sometimes because the press itself has been a little strained. If the
scraper has been made properly, it will adjust itself to the stone, even
if the scraper arm is not quite plumb on the stone, a condition that
often occurs with small work, such as titles and other things that are
at the end of a stone.
(5) For every press a number of scrapers of different dimensions must be
in stock. Generally a lever press is so made that the printing-frame can
be raised or lowered according to the thickness of the stone. Then the
scraper must be changed accordingly.
(6) The connection of the upper board with the tread is made by a thin
stick that is fastened to a lever below, by means of a small iron piece
which contains several holes that serve to adjust the height of the
tread according to need.
(7) The leather in the printing-frame is strong calfskin. It must be
stretched very evenly and tensely and must be smeared from time to time
very thoroughly with tallow.
(8) On the outer side of the frame there are four wooden strips that can
be adjusted as desired. One serves to show the point where the
impression is to begin. Another shows where it is to end. Both must be
so strong that they can resist the scraper. The other two are adjusted
at the sides and guide the scraper.
V
THE CYLINDER PRESSES
When Herr Professor Mitterer installed a lithographic institution for
the Feyertags-Schule, the lever press appeared to him to demand too much
labor, especially when powerful pressures were desired. He invented the
so-called Cylinder or Star Press, which has its place in most
establishments, especially those in other countries. It has had minor
changes made in it by many persons, but on the whole, nobody has
succeeded in improving it notably, except for a considerable improvement
made by Herr Mitterer himself. My description will include this
improvement.
The cylinder press might almost be called a reversed lever press. Herr
Mitterer borrowed from it the idea of effecting the impression with a
scraper, but he did not let it move over the plate, as in the lever
press. He gave the scraper a fixed, immovable position while the stone
was drawn through underneath, thus making his press resemble a
copper-plate printing-press somewhat.
Illustration number 4 shows this machine in the moment when the
impression has been made. In the middle of the machine is a cylinder ten
to twelve inches thick and as long as the breadth of the press. It has
strong iron spindles that revolve in well-lubricated brass bearings.
Above the cylinder is a board on which is fastened the stone with the
printing-frame. The scraper is on a strong lever that is held up by a
counterpoise. When everything is ready for printing, the scraper is
forced down. By means of a strong iron hook it engages the treadle and
thus can be pulled down with the utmost tension. Then the cylinder is
turned by means of two levers affixed to the crank, and this draws the
stone and printing-frame through under the scraper. One workman alone
can do this under ordinary pressure, but an appliance at the other end
of the press enables a second workman to help.
VI
GYRATING SCRAPER AND DOUBLE LEVER PRESSES
I have already mentioned the gyrating scraper press. I have improved it
considerably. It has the form of the ordinary lever press, but all the
parts can be much lighter. For instance, the lever is only one and a
half inches thick. The spring (the elastic board) is very elastic and
need exert a pressure of only one hundred pounds. The little scraper is
only an inch long and presses on the plate with a force of fifty pounds.
The press is useful for very thin stones that might crack under greater
pressure. The pressure, nevertheless, is great, because it is all
exerted on such a small area. The press has two defects. It is easy to
miss many parts of the design with the small scraper, and the paper is
likely to stick to the leather, producing poor register. I have obviated
these faults with the following invention: A large scraper is fastened
to the lever to press on the plate with a force of one hundred pounds. A
small one is fastened to this in such a manner that it can be moved to
and fro easily. While one workman rubs to and fro with the small
scraper, another draws the entire stone and printing-frame slowly along
under the large one. If good underlays are used in addition, this
process will produce beautiful work that cannot be produced so well with
any other machine. However, a large field is left in this form for
improvement.
The fact that the concentric motion produced by a single lever can be
transformed into an almost straight motion by use of a second lever, led
me to design a double lever press, which has turned out very successful,
giving great force with speed. As its description would demand much
space, and since on the whole it ranks equally with the improved
cylinder press, I offer to send models to those who desire to have
everything useful for the art.
VII
THE OTHER STONE PRINTING-PRESSES
The cylinder press of the Chemical Printery in Vienna would, without
question, be of excellent service for the art if it were more powerful.
Its construction is as follows: The stone is fastened to a table with
the printing-frame which has fine felt instead of leather. To make the
impression a brass cylinder eight inches thick is rolled over it. As
this cylinder would not produce enough pressure from itself, despite its
massive make, two iron beams are fastened to the axles. They pass
through the table and are fastened to a box that contains iron or leaden
weights. Unfortunately the space prevents the use of more than five or
six hundredweights, and this is too little for the large surface of the
cylinder, thus forbidding any sharp, clear impressions.
This kind of press could be greatly improved if it were built higher to
give more room below for weights, or the beams could be lengthened and
passed through the floor into a lower room, thus giving space enough to
add weights up to fifty and more hundredweight.
The press of Herr Andre is much like this, except that its cylinder is
only three inches in diameter and that it is forced on the stone not
with weights, but with a lower cylinder that presses upwards. It prints
fast, like the other, but does not possess enough power.
In conclusion, I must remark that the concentration of ideas caused by
writing this chapter has led me to begin experiments toward making a
lithographic press which shall leave nothing to be desired. As soon as
my affairs permit, I shall execute this on a large scale, and if the
result fulfills my hopes, it will be a pleasure to describe it
accurately to all friends of my art, or to furnish them models at cost.
PART II
CONCERNING THE VARIOUS METHODS
There are two principal methods of stone-printing, Relief and Intaglio.
In the former, the fatty parts of the stone are not attacked by the
etching fluid, while the rest of the stone is dissolved more or less.
Therefore the fatty places are left in relief.
In the second method, the design is either engraved into the stone with
a sharp steel instrument or etched-in with acid.
The relief method has the advantage of greater speed and, generally, a
greater number of impressions. It is easy for the artist to apply,
especially in crayon work. The intaglio, however, makes possible finer
and more powerful work, and again, in many cases, is the easier of the
two for the artist. Therefore it is impossible to say in a general way
which is the better. It depends on the work to be done.
CHAPTER I
RELIEF METHOD
To this method belong principally: (_a_) Brush and pen designs; (_b_)
the crayon method; (_c_) the transfer method; (_d_) the wood-cut method;
(_e_) a sort of scraped style; and (_f_) spatter-work.
I
BRUSH AND PEN WORK
This is one of the best in lithography, and perhaps the best, because it
touches daily needs most directly. It can be used not only for all
kinds of writings, but also for illustration that does not demand the
supreme perfection of copper plate. The ease of manipulation, the speed
and the almost countless number of impressions recommend it especially.
It may even be prophesied that in future, when true artists have become
better acquainted with it, it will be used for high forms of art.
Much as this method has to recommend it, it has been used mainly for
script and music, and it is difficult to gain adherents and followers
for it. The reason is an apparently trivial thing, but it has made most
artists averse to it. Since stone-printing exists I have found only two
persons who could do anything with the steel pen at the first attempt.
These were my brother Klemens, and a Herr Porner, who works now in the
establishment of Herr Müller in Karlsruhe. All others have had to
struggle more or less with this slight trouble, and yet it does not
demand more than a few days of patience and study.
For pen work one must not be too particular in selecting stones, as the
less perfect ones are more available for this than for any other method.
However, the general rule holds good here, too, that the purest and
hardest stones are best.
If they have been used previously, so that the fatty inks have
penetrated pretty well, they still need not be ground too deeply, but it
will suffice to grind them merely till all depressions and elevations of
the previous design have vanished. They may be ground with sand or
pumice, so long as they are made smooth so that no roughness can be
perceived. The smoother and finer the surface is, the easier will it be
to work on it with the pen.
To design well on stone with chemical ink, the stone must be prepared
after grinding so that the ink shall not flow and spread. Dissolve one
part of tallow in three parts of oil of turpentine and coat the dry
stone very quickly. With a clean rag or tissue paper wipe it at once so
thoroughly that the coating vanishes again almost entirely, leaving only
a thin film that can be easily devoured and removed when the etching
fluid is applied later. It is well to do this some hours before
beginning work on the stone, partly to give the turpentine odor time to
evaporate and partly because it is easier to work after a little while
than immediately after coating the stone. The stone can be prepared far
in advance, even so long as some months before using. In that case it is
necessary merely to clean the dust away with a cloth or fine brush. This
should be done anyway at intervals during the work, or it will clog the
pen.
I prefer another way of preparing the stone for designing, because
it is one that insures the stone against containing any hidden
preparation, which can easily occur in grinding owing to carelessness or
uncleanliness on the part of the workman, especially if many old plates
are being reground, when the gum which most of them contain from
previous use will mix with water during grinding and thus form a partial
preparation of the stone.
I coat the plate with strong soap-water containing many soapy particles,
and dry it off as well as possible. Now, there will be too much alkali
on the plate, which will not be good for fine work. I pour a few drops
of clean water on the stone, make it quite wet with this and dry it
again thoroughly. The fat of the soap will then have precipitated itself
on the stone and at the same time has lost all alkali. The soap-water
must not be too thin, as in that case it will precipitate too much fat
on the plate at once and the etching fluid will not be able later to
destroy it properly. This would mean the total destruction of the
design. To make quite sure, I advise beginners, after applying
soap-water and drying it, to coat the stone with the tallow and
turpentine solution, clean it quickly, and thus be absolutely assured
that the plate is thoroughly prepared for the design.
It must not be imagined that this preparation for work is not very
important. I am convinced that less depends on the quality of the ink
than on a surface freed from all acid and mucous substances and provided
with a sufficient amount of fat.
On the stone thus prepared the rough design may be done with lead crayon
or red chalk or by tracings or transfers. Any surplus of lead or red
chalk would make trouble during the succeeding completion of the design
with chemical ink, and must be removed carefully. If the design has
been laid on by transfer, the resultant fattiness must be lightly rubbed
away with a fine sand, but not so as to injure the design.
This method, of first drafting the design on paper with soft chemical
transfer ink and then transferring to stone, offers such advantages that
it pays to practice it. Care must be taken to remove all surplus of
color, as otherwise all lines that should not appear will resist the
etching fluid and gradually show again. Those who fear destruction of
the design by the use of sand can effect the same purpose by printing
off on clean waste paper a few times, or the design may be printed off
on paper before being transferred, thus cleansing it of surplus fat.
When the design has been laid on the stone clean and strongly with
chemical ink, the plate can be etched and prepared, but not till the
whole design is perfectly dry, because otherwise it cannot resist the
action of the fluid.
The parts finished first usually are dry long before the entire work is
finished. A trained eye can recognize the proper degree of dryness from
the sheen, which varies with different kinds of ink, but on the whole is
always duller when the design is dry than while it still is wet. It is
highly necessary that the design be thoroughly dry. It is possible to
keep a designed plate for years without etching it, so long as it is
protected against injury.
Etching is done in two ways, painting the fluid on and pouring it on.
The former method is less circumstantial, but is used only in coarser
work, because there is always danger of damaging delicate parts of the
design. It has the advantage, however, that any dirt caused by
corrections will be removed. A mixture of three or four parts of water
with one part of aquafortis is painted over the stone with a soft brush
of fox- or badger-hair. The brush must be dipped continually because the
fluid loses its power.
For the second method the stone is placed in a large wooden trough or
box, provided with cross-pieces to keep the stone from the bottom. The
acid, thinned down with thirty or forty parts of water, is poured over
it. It is rather immaterial how much one may dilute the acid. Very weak
solutions simply mean that the pouring must be repeated oftener. The
fluid acts on stones according to their degree of hardness. Regard must
be had, too, to the delicacy of the design, very fine lines being unable
to resist etching that does not affect coarse lines.
Only slight experience is needed to recognize the effect of the acid. By
looking at the stone sidewise and against the light, the growing
elevation of the design can be perceived easily. When the fatty coating
caused by the soap or turpentine wash has been etched away completely,
and the water adheres equally everywhere, the stone generally is
sufficiently etched to be ready for preparation and printing.
For the sake of easier printing, and also so that future grinding and
any desired improvement may be done on the stone, there should be a
little more etching, if the design is not too delicate. But if the
design is very fine, the etching absolutely must not be more than
strictly necessary, because the fine lines might easily be eaten away.
Coarser designs can bear strong etching which often may reach the depth
of a thick paper. But an inordinate amount of etching is not to be
recommended, even if the design can bear it, because the edges of a
deeply etched line are rough and take the color so strongly that it
works into the cavities and is very hard to get out.
When the stone has been properly etched, clean water is poured over it
to wash away the free acid. Then the work of preparing the plate with a
solution of gum arabic in four or five parts of water can begin at once,
or the stone may be set aside to dry, thus giving the finer parts of the
design, that may have been most affected by the acid, time to adhere
again to the stone and soak in, which can occur only in the dry state.
This is entirely unnecessary with most pen drawings, but with brush and
especially with crayon work it is of great value.
When the stone has been prepared with gum, it is set aside to rest for a
few minutes. Then pour a few drops of water and exactly the same
quantity of oil of turpentine on it, spread it in all directions
uniformly and wipe the entire design off clean with a woolen rag. Hard
ink, especially if it has been on the stone for some time, is more
difficult to remove and a little more turpentine is required.
The stone should now be inked-in at once, because the turpentine, and
with it all the fattiness, is liable to extensive evaporation, and then
the stone will not take color well.
Inking-in of the pen designs is done as follows: A clean linen or woolen
rag is soaked in clean water and wrung out till it is damp rather than
wet. This is passed over the whole stone so that it becomes a little wet
everywhere. Immediately after this dampening, the well-inked
printing-roller is passed to and fro over the plate several times. The
roller must be lifted frequently during this work so that the points of
contact change. To lay the color on well and quickly, the roller should
be held rather firmly in the beginning, well pressed down and used with
a certain rubbing motion that will tend to lay color on the design
sideways, so to speak. Then the roller must be allowed to roll to and
fro a few times without much pressure, to spread the color and take away
any surplus. Do not roll too long, till the stone dries, because then it
will take dirt immediately. Should this occur, it must be wiped
instantly with the damp cloth till it is clean again. If dirt is left
too long, it will be extremely hard to remove.
Beginners usually wet their plates excessively to counteract this
trouble of drying during the inking-in. This results in wiping away fine
strokes, and the roller gets so wet that no good impression can be made
till it has been dried sufficiently again. For this reason beginners
should not use bath-sponge, because, though it is excellent, it leaves
too much water on the stone unless one knows exactly how to use it.
Some printers put a little gum, others a little aquafortis into the
water to wet the stone. Others use stale beer, or even urine. I consider
all this unnecessary, if the stone has been prepared correctly and the
color is good.
I have described the ink-rollers. I repeat that they must be uniform,
soft, and elastic.
As to the inking-in color, I am not able yet to lay down a strict rule.
All that I can say, as a result of my experiments and experiences,
is:--
(1) The firmer the varnish in a color is, the cleaner is the work of
inking-in.
(2) The same is true the more lampblack it contains.
But in both cases the finer parts of the work are easily rubbed away,
and too much lampblack makes the lines squash the impression.
(3) The toughness or fluidity of the color must bear correct proportion
to the power of the press. The harder the varnish, the more power is
required in the press.
(4) Tough varnish is not so liable to squash under pressure, but if it
has once been pressed into the spaces between the lines of the design it
is not readily removed by the mere action of the inking-roller, and this
causes more and more smutting and, finally, total ruin to the stone.
Generally when a tough color has adhered too much, there is no other
remedy than to clean the stone well with gum and oil of turpentine; and
this, if done too often, damages the preparation and makes the
impressions continuously poorer.
(5) Soft color spreads more readily under pressure, but is removable
after each impression by merely dampening the plate.
(6) In using soft color, the paper may be kept damper than with hard
colors.
(7) Soft as well as hard printing-color, if not mixed with the proper
amount of varnish, has the property of producing poor, sooty impressions
because of a defect called shading. Shading is caused as follows: If a
drop of oil falls into a basin of clean water, a part of the oil will
spread immediately. Now, a stone is wetted before inking-in. After the
inking a considerable portion of dampness remains. If the ink is very
fluid, it will happen often that a part of it will spread away from the
design to the surrounding moisture, producing something that looks like
a shadow around every part of the design. This does not occur instantly,
as in the case of the pure oil, but gradually, so that it is not as
noticeable when the swifter lever press is used as with the slower
cylinder press or if the workmen are slow. If a stone can be dampened so
exactly that with the last touch of the ink-roller the last vestige of
dampness is removed, this is not likely to happen. But it is difficult
to arrive at such accuracy. It is better to add enough lampblack
gradually to the varnish to make it lose its elasticity, when the
shading effect will cease.
(8) While shading is obviated largely through enough intermixture of
lampblack or other coloring substances to take away the fluidity of the
printing-color, this intermixture will cause other troubles. The finer
places will not take the harder color so well, whereas at other places
too much will be taken. Also an impression made with much lampblack will
off-set more than one made with color in which varnish predominates.
Neither will the impressions be so black. Experience teaches that a
printing-color that has less lampblack will be blacker, because the
sheen of the varnish will make the color strong and lacquer-like. I have
tried to invent a kind of varnish that would not be so liable to shading
and thus would permit a greater fluidity with safety, but lack of time
has prevented me from exhausting the possibilities. I am sure, however,
that it can be done, for I have found that the common linseed oil
varnish can be made to lose its property of shading by admixture of
fatty and resinous bodies. For instance, the addition of a slight amount
of Venetian turpentine permits a greater fluidity. Very good is the
following composition: Six parts linseed oil, two parts tallow, one part
wax, melted together and thickened by boiling down and burning like the
ordinary linseed oil varnish.
(9) The inner composition of the stone and the temperature have a
considerable effect on the print and also react on the color. A stone,
especially a porous one, has much less internal moisture on very warm,
dry days. Then the dampening done before each impression often
evaporates instantly and unequally, so that it is difficult to ink-in
uniformly with a soft color or one lacking varnish, unless one wets the
stone unduly, which, again, injures the impressions. In that case one
must use a color that is firmer than should be used according to
ordinary rule. It is also well, before printing from the stone, to lay
it in clean water for a few hours, or overnight, so that it may soak in
enough moisture to make it easier to dampen.
(10) If the drying of the printing-color is to be hastened, as is
necessary with some work, a little finely powdered mennig may be mixed
in. Finely powdered litharge of silver dries still better, but only a
small amount of printing-color must be mixed with it, because it
toughens within an hour. It will not keep for another day, because the
mennig will dissolve after a while.
In printing from the pen design, the following must be observed:--
Even if the stone has been inked-in uniformly and well with a good
color, the impression can be spoiled in various ways: if the paper has
not been dampened as required by the nature of the color and the power
of the press; if the pressure is not in proportion to the consistency of
the color; if the scraper is not even, and if the leather is not
properly stretched.
Therefore care must be taken in printing pen designs:--
(1) The paper must not touch the inked design till the scraper forces it
down. It is not advisable to lay the paper directly on the stone. It
should be in the printing-frame, which, as already described, should be
so arranged that it will keep the paper at least one fourth inch away
from the stone.
(2) The proper dampening of the paper is not a matter of the greatest
importance in pen designs, so long as it is not too wet, in which case
it causes squashed impressions, does not take color uniformly, and, if
the printing-color is tough, will stick to the stone. In general, the
rule holds good that the degree of dampening must be in proportion to
the firmness of the varnish, and that a softer varnish permits increased
dampening. Dampening is done chiefly to soften the paper, and the
qualities of the paper dictate the amount necessary to a large extent.
(3) The tension of the press must be more powerful with hard
printing-color and carefully graduated with soft color. Besides this, it
depends--
(4) On the structure of the scraper. If it is not absolutely uniform and
well fitted to the stone, more power is needed. Thus the defect often is
corrected; but this may make the color squash and spread in other spots,
therefore it always is better to correct any defects in the scraper. The
sharper the scraper is, the clearer are the impressions, because then
the whole force of the pressure concentrates on the smallest area. But
usually the scraper soon becomes dull, and then the press must have
more power.
(5) Insufficient tension of the leather also may produce poor
impressions, especially if the color is soft and the paper very wet.
Therefore as soon as impressions appear blurred and squashed, the
leather should be tautened and well lubricated with tallow.
Now we come to an important matter, namely, the correction of errors. It
does not happen often that a drawing or inscription can be made entirely
without error, and it would be a great imperfection in lithography if
these mistakes could not be corrected at once.
Errors may be observed before etching or afterward. Different ways of
making corrections are required.
It is very easy to make corrections before etching. If the error is
observed as soon as it is made, while the ink still is wet, it may be
corrected by merely wiping out the defect with the finger. If the ink is
dry, oil of turpentine is required. In each case the ink must be well
removed so that it will not resist the etching fluid later. If only tiny
spots are defective they can be corrected by delicate use of a sharp
eraser. Defects that need merely to be destroyed without drawing
anything else in their place may be scraped off with a knife or with
pumice stone.
After the plate is etched, errors demand treatments that differ
according to whether a defect or blemish is merely to be removed,
whether something else is to be drawn in place of the removed part, or
if something has been forgotten and is to be added. The area of the
correction also makes a difference.
If it is only a matter of removing small defects or places, delicate
erasure will do. The same, or polishing with pumice, is done if the area
is larger. Then the corrected spots must be coated with a mixture of gum
and aquafortis, using a soft brush very carefully that it may not touch
any of the sound places.
If something new is to be drawn in, the process is different. Ink-in the
stone very clean, and coat it with gum and water that is very thin and
delicate. Let it dry. Then scrape the defective places away very
carefully or grind them away by rubbing with pumice stone. Coat the
spots cautiously with soap-water or oil of turpentine and clean off
again as thoroughly as possible. (This coating is not necessary in the
case of a few isolated small lines or points.) Now draw in your new
design with chemical ink, and as soon as this is dry, etch the
corrections carefully with a small brush and then prepare with gum.
The third case, where something has been forgotten, is treated almost
the same way. If it is only a very small thing, the stone need merely be
scraped carefully. Then the drawing may be put in, preferably with a
thicker ink. If the area is large, the stone must be ground where the
design is to be added, coated with soap-water or oil of turpentine, and
then treated as explained before.
When the stone has been corrected and prepared for printing, it can be
used at once or set aside for some length of time. In the latter case it
should be inked with a firm color and coated delicately with gum
solution. Then it can be held as long as desired. Coating with gum
solution is advisable not merely for storing away, but for every
interruption of printing that lasts more than five minutes.
If a stone has stood longer than a day without being freshly inked, it
must be wiped off first of all with gum solution and oil of turpentine,
that it may take the color well, so that the very first impression may
be perfect. During the progress of printing, the following points are
important: Uniform distribution of water, the same of printing-color,
frequent inking of the inking-roller, and the very greatest speed
possible.
In the main points the brush process is like that of the pen. The chief
difference is that it is not possible to make the brush strokes as
strong as those with the pen. Therefore, brush work does not resist
etching so well and must not be treated too powerfully. Much depends on
the treatment of the brush and the consistency of the ink. The brush
does not permit such a flow of ink as does the pen, and generally
requires one that is more fluid. A good brush ink is made as follows:--
Mix two parts of pure white wax and one part of good tallow soap into a
mass not larger than a hazel nut. The ink loses its good properties
quickly and should be made fresh day by day. Mix the two materials with
a thick knife on a lukewarm (but positively not warm) stone, separate
into small parts and moisten with rain water. As soon as the water has
softened the mass a trifle, add as much lampblack as will lie on two
knife points and mix the whole mass together once more till it is
thoroughly mixed and quite firm. When required, a bit of this is rubbed
down in a clean saucer with rain water.
As a better flow of ink is needed for brush work than for pen work, it
is evident that it would not be requisite to treat the stone with
soap-water and oil of turpentine, as for pen work. However, it often
pays to make certain fine lines with the pen, and therefore it is better
to combine both processes and prepare the stone as for pen work. It is
well, however, after drying the coating, to rub it very gently with dry
sand, which will not make the pen strokes flow to any extent and still
will prepare the stone so that it will take the brush strokes well and
not make necessary such strong etching.
If a brush design is to be etched in high relief, for ease in printing
or for durability, it must be etched only to the extent absolutely
required at first. Then it must be prepared with gum and inked-in with
good acid-proof color. Set it aside for a while, that the color may
concentrate so that it will resist the acid well, and then etch the
stone to the desired degree. After etching, wash with water, coat with
gum and put aside to dry. Owing to this latter procedure any fine parts
that may have been unduly affected by the acid will adhere to the plate
anew and it can be printed then like a pen design.
If pen and brush work are to be combined on a stone, and absolute
certainty is desired, that even the very finest lines shall not suffer
from etching, the following process will serve:--
Over the cleanly ground plate pour a solution of weakened but pure
aquafortis, about forty parts of water to one part of aquafortis. Repeat
this several times. Then pour a great deal of water over the stone, to
wash off all acid, and let it dry. Pen as well as brush work is easy on
such a stone, by using the proper ink for each method. When the work is
finished and dry, the stone is merely coated with gum solution. After a
few minutes it can be inked-in with acid-proof ink and treated as
described before.
II
THE CRAYON METHOD
The fat of the chemical ink penetrates the stone in dry form as well as
in fluid form, and makes the plate receptive to printing-color. If the
dry ink is cut into long pieces and sharpened, it can be used much like
lead or black crayon. If the stone is ground very smooth, the work can
be made quite fine and resembles that done with fluid ink. The crayon,
however, wears away too quickly. If the stone is ground rough, so that
instead of a polished surface it has one resembling rough paper, the
crayon work appears as a mass of dots that are coarser or finer
according to pressure with the crayon, and produce an effect similar to
crayon designs on paper. As almost every artist and painter knows how to
use crayon, no particular practice is required for working on stone, and
there are no obstacles such as the difficulty of using the steel pen.
That crayon work on stone is capable of high perfection, and that it can
represent the essentials of a painting in a manner scarcely to be
excelled by the best copper-plate engraver, has been demonstrated by
many successful productions. Add to this that in no other style can one
work equally fast, either on copper or stone, and we see that the crayon
method is a genuine advantage for the art.
For crayon work the stones must be uniform and hard. They must either be
new, or, if they have been used, they must be ground so thoroughly that
all traces of fat are destroyed and removed absolutely to a degree where
it is certain that they will not appear again and take color, even if
the stone is etched only lightly. As soon as the plates have been ground
true, they must be grained by strewing some fine sand or powdered
sandstone on them and rubbing in all directions with a small piece of
limestone. The work can be done dry or wet. Soap-water is best. It gives
the stone a handsome grain. Practice is demanded to get good results
without scratching the stone. The artist must decide for himself what
grain he needs. I think that it would be good if the artist himself were
to grain the stone in varying degrees according to the need of his
design. For instance, a coarser grain might be good for foregrounds.
As soon as the stone has been grained, it must be cleansed perfectly
from dust and dirt. It is best to pour clean water over it and wash it
with a clean rag. The dust and sand must all be removed, otherwise they
will not let the crayon reach the stone where it is used delicately.
When the design is finished, it should be set aside for a day, that it
may take good hold of the stone. It does no harm to let plates rest for
years before etching. Etching must be done by pouring. Painting the
etching fluid on is dangerous because of the danger of taking away fine
spots. About one hundred parts of water are used to one part of
aquafortis. Everything depends on not etching a bit more than necessary.
It is best to etch the coarser parts specially with a small brush and
stronger etching solution, and it is very good to wash the stone with
clean water after etching and let it dry completely before coating with
gum.
When the stone has been prepared, it should not be cleansed at once with
oil of turpentine, but should be inked-in first with a light
printing-color. Only after it has taken this well should it be cleansed
of the crayon and treated to a firmer color. In the first inking-in
there should be very little pressure with the sponge or wet cloth when
dampening it, as the lightest parts of the design are easily rubbed away
before they have taken color. If such parts should vanish, the easiest
way to restore them is as follows:--
Coat the plate with gum solution and wipe with a clean dry cloth till it
is perfectly dry. Then take a flat, knife-like instrument of steel,
which is cleanly ground so that it has no nicks or other defects that
might injure the stone. Scrape with moderate pressure to and fro over
the defective places, but only so that it touches the elevated points
and not the surface of the stone itself. Smear a little fat, such as
linseed oil varnish, over it and wash this away again instantly with gum
solution. Generally the parts all reappear very nicely when the stone is
inked-in again.
A second kind of correction is as follows: Ink the stone with firm
color, wash it well with plenty of pure water and let it dry. Now redraw
the lost places with crayon.
Printing crayon work is the most difficult of all lithography, but can
be done perfectly if all necessary precautions are taken. These are
mainly: (_a_) proper dampening of the paper; (_b_) perfect dampening of
the stone;--too much meaning that the fine points will not take color
well, too little making the stone smut easily; (_c_) good stretching of
the leather, industrious lubrication, and an underlay of taffeta; (_d_)
a good, finely mixed inking-color that will not shade off in printing
and yet does not contain too much lampblack; (_e_) soft and well-dried
ink-rollers; (_f_) proper tension of the press; (_g_) utmost possible
speed in printing. The latter aids enormously, because the stone does
not get so much time to dry out.
Aside from the spreading and running-together of the darker parts, one
of the commonest faults of crayon work is that it is very liable to get
a tone, which spreads over the whole design like a veil; or that the
designs lose their firmness and appear "monotonic" because the shadings
spread and thicken. The first fault comes from weak etching or from oil
that was rancid when it was used to prepare the varnish. The latter
fault makes the color adhere and smut the stone. The same fault is
developed if the printing-color contains soap, which some printers mix
into it for better adherence. It can occur also if the stone has lost
its preparation owing to frequent cleansing and strong rubbing with a
dry rag that is inky. Even strong rubbing with clean water can cause it
if the rag contains fats.
As to the "monotonic" effect, it is frequent, and I have learned that it
can be caused in two ways, namely, if the color is squashed continually
during the print, which makes the stone sooty; or if the color spreads,
as, for instance, during the night or during the noonday rest. The stone
is prepared only on the surface. In the pen style, all lines are
prepared on the sides also, so that they cannot spread because they are
considerably more elevated than the crayon designs.
If a crayon design dries after printing and is not coated properly with
gum, the color is liable to spread away from the design and give the
plate the before-mentioned tone. Even if it is coated with gum, the
color will spread, at least in the inner parts of the stone; and as soon
as the very thin surface has been at all wiped away by rough usage, the
underlying fattiness will appear gradually, and begin to take color.
Both faults of crayon work, namely, the taking of tone and the
development of a "monotonic" condition, can be remedied by inking the
plate for a while with a firmer color. If this does not help, the
following must be resorted to: Ink-in the plate as well as possible, lay
it in the etching-trough and pour over it very weak aquafortis once or
twice. Then wash it with pure water and paint the gum solution over it.
The etching must be done with great caution, with a solution so weak
that the acid is scarcely perceptible. If the plate is to be saved at
all without extensive corrections and re-drawing, this is the best way.
If it is done correctly, it harms the design so little that I advise it
even when the plate looks quite well, but has been standing very long
after the first printing.
I have etched several crayon designs over again, and rather extensively,
to make them more durable and facilitate printing, and with good
success. This gives the further advantage that corrections can be made
at the same time.
The correction of crayon designs, that have been etched already and used
for printing, always has been so difficult a task that few have
succeeded. This has led me to give the matter my best attention; and I
hope that the following rules, based on many experiments, will show the
way, at least, even if they do not produce absolute results.
When a copper-plate engraver has partially finished his plate, he can
have a proof pulled to enable him to study his work. Then he can make
corrections as he pleases,--an advantage that the stone worker has
lacked hitherto.
To produce an impression that shall be faithful to all the beauties of a
crayon design is a matter dependent on so many trivial details that of
the many hundred crayon designs that have been produced by lithographers
since the origin of the art, hardly one has realized the designer's
hopes and ambitions. The commonest fault is that the more delicate
parts of the design print too light and the heavier ones too dark,
thus destroying the balance of tones. The lightening occurs because
the finest parts of the design have lost their power of taking
printing-color. The darkening occurs because the closely shaded parts
flow together, either because the etching has not made enough white
space between the points and lines or because they are squashed in the
pressure of printing.
From this, two other faults may arise, that become visible after
inking-in the plate: The first is the appearance of white dots,
sometimes pretty large. The second is that black dots and smut-marks
appear.
The white dots are caused by speaking during the work, and thus dropping
spittle on the plate. If the spittle is mucous, the plate covers itself
there with a fine crust that resists the chemical crayon so that it does
not soak into the stone and is wiped away by the inking-in. If the
spittle is fatty,--for instance, if one has eaten anything greasy,--the
dots that appear will be black. The same results from touching the plate
with fatty hands. Sometimes a whole picture of the fingers and skin will
appear on the impression.
Let us suppose that after inking-in, a plate shows all these faults: the
finest shadings vanished entirely, the darker places run together, white
and black dots and smut-marks so that the plate has become useless in
every respect. Can this be remedied? If so, how?
I answer that it can be remedied in every point; but that the artist
himself must decide if it will not pay better to do the whole design
anew.
The second question I answer as follows:--
Before everything else, it is necessary to remove all that should not be
on the stone, all smut-marks and black dots; and where the design has
darkened, white points or lights must be graved-in. To accomplish this,
the stone is inked-in first with a firm acid-proof color, and over this
with a lighter one. Then erase or grind away the dirt that is outside of
the design and that would dirty the margin of the printing-paper. No
erasing or grinding must be done within the design itself because then
the grain would be destroyed and the necessary drawing could not be done
as it should be. Therefore the faulty parts must be removed by
engraving, with a more or less sharp needle of good steel, so that what
remains looks quite like a good grain. A little practice will show that
this work is not at all difficult and can be done quickly. Places that
have run together can be cleared and made transparent and clean in a few
minutes. If certain points have become too large, they can be corrected
by engraving a white point in their centre or by engraving a line
through them.
Here I must note that parts of crayon designs thicken sometimes because
the crayon has slipped in drawing, without leaving traces perceptible at
the time. If the etching is weak, it may happen easily that this place
takes printing-color. Skillful engraving may not only correct the
defect, but actually gives the design a beautiful tone and power such as
cannot be easily produced by the crayon itself.
When the plate has been cleansed thus of all surplus and blemishes, weak
aquafortis is poured over it several times and then it is coated with
gum. After a few minutes it is inked-in with fairly firm color. Then it
will be seen that the design is clean, but that all the parts that were
too light are not darker, but perhaps even lighter, having been affected
by the etching. To remedy this, coat the stone with gum solution and
then wipe it off with a dry clean rag so thoroughly that only a thin
film of gum remains behind. To judge this better, it is well to mix a
little red chalk with the gum. When the plate is wholly dry, take a
knife-like tool of steel as described before, and scrape the defective
parts under moderate pressure, without injuring the elevated points of
the design. Great care must be taken during this process to let no
moisture, not even the breath, touch the stone, because that would
produce the very opposite of what is aimed at. When all faulty places
have been treated, a little tallow or linseed oil is smeared over the
plate and then washed away well but gently with thin gum and water. If
this manipulation has been done accurately, the lost parts of the design
will appear when the plate is inked with a somewhat softer color.
Those who fear that they do not possess the skill necessary for this
rubbing-up of the defective parts may attain the object by re-drawing
them. The stone must be washed off first with a great deal of very pure
water and the crayon must contain much soap. This kind of correction
must be finished as quickly as possible and the stone should not be set
aside for any length of time without a gum coating. If the corrections
are extensive, it is better first to ink the stone well with acid-proof
color and then to wash it in pure water and let it dry. Then if it is
inked-in after the design is finished, and if weak aquafortis is poured
over it and it is prepared with gum, it will keep for several months.
Slight blemishes, white specks, etc., can best be corrected by gentle
touching-up with crayon during the proof-printing on the wet plate. It
is understood, of course, that one can also work with pen or brush in a
crayon design that has been already etched. Parts that are too dark can
be made lighter by passing over them a few times with a brush dipped in
weak aquafortis and then re-coating with gum.
These are about the best ways for correcting a crayon design that proves
after etching to be imperfect.
I close with the following:--
(1) The tanners of Munich manufacture an inking-ball, made especially
for printing, of sheepskin, such as I could not obtain in other places,
like London, Offenbach, and Vienna. It is not white like alum-dressed
leather, but yellowish, and the oil has not been completely washed out.
I have had dogskin and thin calfskin worked in the same way and have
found them even better, because of their greater durability. If a roller
is covered with this leather, so that the side that was hairy comes
outermost (not innermost as many do), it develops a decided property of
taking-on color, probably because of its smoothness and elasticity. This
aids much in spreading the color uniformly over the stone. The property
is increased if the roller is dampened slightly before being inked; but
on the contrary, if the stone is kept too wet, the constant moisture
will gradually prepare the roller, so to speak, and it will take less
color and let it go quickly, thus inking the stone badly.
If a roller has been used a long time, it loses its elasticity and
softness and becomes useless for fine work. Still worse is a roller that
has hardened from the drying of the ink. It is surprising to see what a
difference it makes if one has worked for a time with a poor roller and
then replaces it with a good one. It is almost impossible to believe
that the new impressions come from the same stone. I am inclined,
therefore, to believe that the quality of the ink-roller has more effect
on good impressions of crayon and fine pen work than even the quality of
the printing-color.
As stated, it is well to change rollers frequently, and it is wise to
clean them with linseed oil or butter after use to keep them soft and
tender. In working on crayon designs of superior value I advise the use
of new rollers.
(2) It has been remarked before that the color of the stone often
deceives the artist as to the values and proportions of his work and
that the designs always look better on the soft-colored stone than they
do on the glaring white paper. This observation led to printing on paper
tinted like the stone, and the results fulfilled expectations. There
were difficulties however. The very best quality of this paper is
extremely dear, and other qualities had the property of dirtying the
stone, on account of the coloring-matter used for tinting them.
Therefore the attempt was made to print the design on white paper and to
color it afterwards. Here, too, there arose many inconveniences, so that
at last there came the thought of laying a yellow tint over the
impression by means of a second printing. This method proved to be not
only the most economical and quick, but it had the further advantage
that the margins of the paper could be left white, thus enhancing the
value of the design. Hardly had it been used with success a few times
before Herr Piloty conceived the idea of printing the high lights into
the design with white printing-color, so that the impressions would
resemble actual drawings. My experiments toward that end did not result
satisfactorily, because no white oil color will print well enough; and I
proposed that the high lights be engraved into the tint plate and thus
permit the original white of the paper to show. So there came that kind
of crayon impression with one or more tint plates, which has become so
popular that various art connoisseurs hold it to be the triumph of the
lithographic art.
To make and print these tone plates, I have thought out many ways; but
as I am sure that they will suggest themselves to those who have grasped
my text-book, I will describe only the best of them all.
Take a stone of good average quality, the best not being essential, and
grind it as for crayon work with a grain not too coarse. When it is
clean and dry, cover it uniformly with the following chemical ink, which
must be laid on so thickly that it surely will resist the aquafortis
sufficiently, yet not so very thickly that it will hinder the drawing-in
of the lights later on.
The chemical ink for use on the tone plates is made of four parts wax,
one part soap, and two parts vermilion. The two first materials are
melted in a clean vessel over a moderate fire and then the vermilion is
stirred in.
A piece of ink as large as a hazel nut is rubbed down in a clean coffee
cup and then dissolved in rain water till it is just fluid enough to lie
evenly and nicely on the plate when applied with a soft brush.
When the stone thus has been painted red, it must be permitted to dry
thoroughly. When it is dry, a strong impression of the design is made on
sized but well-dampened paper with a printing-color rather soft than
firm. Before the paper has a chance to dry and thus to shrink, the red
stone is placed in the press and the impression is laid on it face down.
Use moderate pressure. The drawing will transfer itself to the red
surface, but the paper will stick. Wet it with weak aquafortis till it
is completely softened and permits itself to be removed. Care must be
taken not to spoil the drawing by violent wiping and rubbing.
This method is easier if a special transfer paper is used. Coat
well-sized, very clean paper with a thin paste of starch such as
laundresses use for stiffening linen. This paper must not be dampened
very much, because then it will not take the impression well. It also is
removed from the tone plate by washing with weak aquafortis and it
yields very easily, because the paste lets go of the color readily.
When the design has been transferred to the tone plate, take good iron
instruments and remove the wax surface wherever the high lights are
desired. As the stone is ground rough, the scraping will produce only
small specks at first, because the instrument will touch only the relief
points. The more the scraping proceeds, the deeper it will go, till at
last one reaches the bottom of the coating and thus obtains a white
light. Experts can so manipulate the tint plates that the lights will be
graduated from the softest to the most glaring.
As soon as the lights are drawn in, the margins of the drawing are
scraped the same way. Then the plate is treated to several washings of
pretty strong aquafortis, about twenty parts of water to one part of
aquafortis. After coating with gum, it is ready for printing.
The most important requisite for this printing is a good arrangement
that will insure an exact register of the second impression with the
first, that the lights may appear exactly where they belong.
To achieve this, the practice used to be to draw two register marks on
the stone holding the original design, which were transferred to the
tint plate with the rest of the design. When the first impression was
made, the printed paper was cut away exactly at the marked points, and
laid accurately, on the tone plate, being guided by the two marks there.
This was effective, but it had the fault that the paper had to be
trimmed off carefully for each impression and that the slightest
inaccuracy spoiled the register. However, it is very useful for printing
proofs.
It is far better to have a printing-frame that is so fixed that it will
never shift its position in the slightest degree. To this is fastened a
little movable frame that has two steel needles whose position is
adjustable at will. Lubricate the leather inside with wax and lay a
sheet of white paper on it. See that the tint plate is so fastened in
the press that it cannot stir out of place. Make an impression and take
care especially that the two register marks print off well. Now set the
needles in the little frame so that they will be exactly over these two
marks. If, then, an impression of the design is laid on so that the two
guiding-marks on it come exactly under the two needles, it will, of
course, register perfectly. Of course the little frame must be so
adjusted that it can be folded back out of the way before each
impression, and the printing-frame must hold the sheets of paper so that
they cannot move.
To color the tint plate, use a firm varnish tinted with umber, or any
other color that will give the desired effect. New rollers are best,
insuring a fine, even, unspotted tone.
(3) In rough-grinding the stones, it is difficult to prevent scratches
and furrows caused by the coarse sand. No design of value should be made
on such a stone, but if one is used, the defects should be touched up
with chemical ink and a fine brush, as crayon will hardly do it.
(4) As the delicate places in crayon work are not durable, etching
having the property of reducing the light portions and darkening the
darker ones, I tried the method of drawing the lighter portions on a
separate stone in rather stronger manner and printing from it with paler
ink. The success was so great that I hope in time to produce true
masterpieces with the aid of skilled artists, and here call attention to
it in advance.
(5) After learning how to make a second impression over a first one, it
is not difficult to pass on to printing with several stones and from
that going on to color-printing. In the early days of my invention I
tried color-printing with a crayon plate and had the best success by
using stencils such as are used by the painters of cards. On oiled stiff
paper I made as many impressions of a design as there were to be colors.
Then all that was to be red was cut out from one stencil, green from
another, and so forth. Then the stone was wetted, the stencil laid on it
and the uncovered parts of the stones inked-in with the right color.
After all the colors had been applied, I made the impression, which
generally looked neat enough, but still resembled a sketchy drawing
rather than a painting, because no color except black, zinc red, and
dark blue permitted itself to be printed strongly enough. But by using
several stones, each of which can be designed and treated according to
the necessities of color, impressions can be made that resemble the
English colored copper prints very closely, especially if the crayon and
pen or brush methods are united.
(6) A stone plate may be etched so that it will have the roughness
needed for crayon work. Grind it as clean and smooth as possible with
pumice, pour aquafortis over it and coat with gum. Wash it well in water
and dry with a clean cloth. Coat it very thinly but uniformly with
tallow into which is mixed a little lampblack, so that one can see if
the coating is perfectly even. With a small ball or roller covered with
fine cloth, roll or pat the stone till it has a very uniform tone. Now
pour a little diluted aquafortis on one end as a test to see if it
penetrates uniformly through the fatty coating. Practice is needed to
hit just the right thickness that the tallow coating must be. It must be
thin, and yet sufficiently thick to resist the aquafortis somewhat, so
that it yields only at those places where the roughness of the cloth on
the roller has removed it more or less.
If the test is satisfactory, make a raised border of wax around the
stone and pour the aquafortis solution on it. A solution of forty parts
of water to one part of aquafortis is better than a stronger one because
the stones are more equally attacked. As soon as the resulting bubbles
are as large as the head of a small pin, the etching fluid is poured
away quickly and replaced with pure water to get rid of the bubbles.
Pour away the water and apply etching fluid again. Repeat this four or
five times, according to the grain desired, and in the end wash the
stone well with oil of turpentine to remove all fattiness. Then it must
be washed with weak but very pure aquafortis, followed by a great deal
of very pure water. After cleaning and drying very carefully with a
clean rag, it is ready for use; and if the work has been well done, a
grain will have been produced that is prettier and much more even than
can be produced by rubbing with sand.
(7) The instructions given here teach how to draw on a stone that has
been prepared beforehand with aquafortis and gum. This is not in the
least inimical to the durability of the design if only the union of the
gum with the stone has been destroyed again by washing afterward with
diluted but pure aquafortis and every trace of this acid again has been
removed by copious washing with pure water. If there is a considerable
amount of the soap in the crayon, the good result will be greater than
with an entirely clean stone, because, since it has already been etched
twice, the etching after the design may be very limited, so that it is
not harmful to even the most delicate shadings in the design.
(8) Some attempts made by me to etch crayon designs more powerfully than
usual proved that the more delicate places would suffer, but if I
rubbed them up with a flat knife as described before, they appeared
again and I had the advantage that the whole plate was much better
prepared than it is with weak etching.
(9) If a crayon plate is spoiled in printing through carelessness or
lack of skill, the rules for remedying the trouble are the same as those
named for pen work, and the judgment of the worker must decide which
method is the most applicable. In general, it may be assumed that the
best remedy for blurred spots is to draw them over again with crayon;
and for smutted parts the best is to apply firmer printing-color, or to
cleanse with oil of turpentine and gum and afterward ink-in with
acid-proof ink, and then use light etching with weak aquafortis followed
always by coating with gum and water.
III
TRANSFER AND TRACING
In the pen and crayon method all the lines that are to take
printing-color are drawn directly on the stone with a fatty preparation.
But lithography has a unique way of transferring to the stone a drawing
or inscription that is first put on paper with the fatty substance. This
is possible only for lithography, and I incline to the belief that it is
the most important of all my inventions. It makes it unnecessary to
learn reverse writing. Everybody who can write on paper with ordinary
ink can do so with the chemical transfer ink, and this writing can then
be transferred to the stone and manifolded indefinitely. In Munich and
Petersburg this method has been introduced for government work. The
measures adopted in council are written during the session by the
secretary, with chemical ink on paper, and sent to the printery. Within
an hour impressions are ready to distribute among the members. I am
convinced that within ten years every European Government will have a
lithographic establishment.
In war the method would have a great value. It would replace the field
printery, and it permits greater speed and secrecy. The commander need
merely write his orders himself and have them printed in his presence by
a man who cannot read, to be sure that his plans will not be betrayed.
The engineer officers can draw plans and have them circulated among the
officers who need them.
Authors and scientists will find the method to be the means of
circulating their works in manuscript very cheaply.
Even artists will respect the method when its gradual perfection enables
them to draw their pictures on paper with ink or crayon and reproduce
them.
Not from boastfulness, but from conviction of the importance of the
method, have I thus recounted its advantages. I could fill a whole book
with detailed explanations. I wish to gain friends for the method, that
it may be improved to its ultimate degree by skilled artists.
The chemical ink used for the paper may be soft or firm. The paper may
be specially prepared or not. The stone may be warm or cold. The design
leaves the paper entirely and clings to the stone, or does so only
partly. To describe all this would take too much space. I will describe
only the method that I consider best, namely, a method under which the
work is done with a soft ink, and transferred to an unwarmed stone. This
is the quickest and surest, and has the advantage of not spoiling the
original.
In a clean coffee cup rub down a piece, as large as a hazel nut, of the
chemical ink described under the heading "Transfer Ink" in an earlier
part of this work. Dissolve with rain water or soft river water. The
amount of water is determined according to the need for fine or coarse
work. In the latter case, the ink should be thinner, that there may not
be too much ink in the design after it dries.
While the writing or design is drying, select a stone that either has
not been used before or at least has been thoroughly ground off, and
grind it down once more with pure and dry pumice stone without water,
until it is certain that all parts of the surface have been rubbed down
so thoroughly that the stone may properly be considered a new one. Clean
away the dust with clean paper, fasten the stone in the press, examine
the scraper to make sure that it is even, adjust the press for the
proper pressure; in a word, do all that is necessary for good
impressions. From this time on the greatest care must be taken not to
touch the polished stone with as much as a finger, not to mention
keeping grease and dirt away from it.
As soon as every point in the design on the paper is perfectly dry, wet
it on the reverse side with a sponge dipped into weak but pure
aquafortis until the paper is quite soft. Lay it between waste paper
sheets for a time, to prevent it from pulling out of shape and to remove
the excess moisture. It must be soft, but not wet, when the impression
is made.
Lay the paper face down on the stone. On it lay two sheets of dry waste
paper, then an equally large piece of taffeta, another sheet of waste
paper and make the transfer print with a moderately swift motion of the
press, which must have more tension than is used for ordinary
impressions. The power of a lever press is insufficient for larger
stones, and a cylinder press is required.