Intenseness of colour.
Impalpability.
Covering the surface perfectly of the type or engraving.
Quitting the surface of the type or engraving when the paper is pressed
on it, and adhering to the paper.
Not smearing after it is printed.
Complete retention of colour.
Ink ought to be reduced to an impalpable smoothness, either in a mill
or on a stone with a muller. This is essential, as the process gives
it the next quality,—that of completely yet very thinly covering the
surface of the type or the lines of the engraving, and insuring an even
and perfect appearance to the impression on the paper. Another important
requisite is, that the ink shall not only cover the surface of the lines
on the paper printed, but that it shall also quit the face of the type
or engraving and leave it quite clean when the paper is impressed on it,
and attach itself to the paper, so as to give a perfect impression of the
subject represented, without the colour of the paper appearing through
the ink; and that this peculiarity of quitting the type or engraving
and becoming attached to the paper shall continue the same through any
number of impressions, without any accumulation of ink on the surface
printed from. After having obtained these results, and when the printing
is as perfect as it can be made by workmanship, something more is
requisite,—viz.: that the ink shall not smear on being slightly rubbed,
and that it shall retain its colour and appearance without spreading at
the edges or tinging the paper.
The rollers should be in good condition; otherwise the pressman may exert
his skill in vain, with a great loss of time and waste of paper.
The quality of the paper is of great consequence in fine printing; but it
is frequently overlooked by the printer’s employers, who are apt to pay
more attention to a showy appearance and a low price than to quality.
The best paper for printing on is that which is made of fine linen rags
and moderately sized, without the use of acids in bleaching, and without
being adulterated with cotton rags: this paper takes water kindly, is
easily got into good condition, receives a good impression, is durable,
preserves its colour, and does not act upon the ink.
The use of cotton rags, the introduction of gypsum into the manufacture
of fine and other papers, the application of acids and bleaching powders
to improve the colour and produce apparently good paper from an inferior
staple,—these form the grand hinderances to the American printer in his
efforts to equal or excel foreign productions. Hence it is that works
printed in this country are less valued than those from the English
press, which are printed on paper of fine fabric, made mostly of linen
rags, and sufficiently strong to bear a fine ink.
A pressman should, as a matter of course, be well acquainted with the
entire routine of presswork; in addition to which, to form his judgment,
he should examine the most splendid productions of the press, and study
them as patterns of workmanship.
In making ready, it must be evident that, when a clear, sharp impression
is wanted, the pressure should be on the surface only. Of course the
tympan ought not to be very soft, neither should a woollen blanket be
used: the most perfect impression will be obtained when fine thick
paper alone is placed in the tympans; and even of this article but few
thicknesses should be employed.
After an impression is printed, the pressman examines if it be uniform
throughout; if it be,—which is very rarely the case,—he goes on with the
work; if not, he proceeds to overlay, in order to produce regularity of
pressure and of colour over the whole form. Wherever the impression is
weak he pastes a bit of thin, smooth paper, of the size and shape of the
imperfect part, on the tympan-sheet; he then pulls another impression, to
examine the effect of his overlays, and continues to add to them where
wanted, till the pressure of the platen is the same in every part and the
impression is of a uniform shade of colour.
If the impression come off too strong in parts, or at the edges or
corners of the pages or on the head-lines, it will be necessary to cut
away the tympan-sheet in those parts, and, if that does not ease the
pressure sufficiently, to cut away the same parts from one or more of the
sheets that are within the tympans.
It is generally preferable to overlay on a sheet of stout smooth paper
inside the tympan, particularly where the same press does the whole or
great part of the work: this sheet is cut to fit the interior of the
tympan, so as not to slip about, and has overlays pasted on it where
wanted, to bring up the impression till it is very nearly equal. In all
succeeding sheets it saves the pressman a great deal of time, as he will
be certain that when he pulls a sheet of another form of the same work
it will be nearly right, and he will only have to place thin overlays on
occasional parts to make the impression perfect.
It is necessary, where short pages occur in a form, to have bearers to
protect their bottom lines and the edges of the adjoining pages. These
may be of double pica reglet, pasted on the frisket, so as to bear on
some part of the furniture or chase; but bearers made to the height of
the types are better, when they can be used.
It happens occasionally that the tympan causes the paper to touch the
form partially on being turned down, and occasions slurs. This may occur
from the parchment being slack or the paper being thin and soft. To
prevent this inconvenience, it is customary to roll up a piece of thick
paper and paste it on the frisket adjoining the part. Many pressmen
prefer pieces of cork cut to about the thickness of double pica, and
pasted on the frisket.
In working the white paper, instead of pins stuck into the tympan, to
prevent the paper slipping, a duck’s bill (a tongue cut in a piece of
stout paper) is frequently used: it is pasted to the tympan at the bottom
of the tympan-sheet, and the tongue projects in front of it; indeed, the
tympan-sheet appears to rest in it. The bottom of each sheet is placed
behind this tongue, which supports it while the tympan is turned down.
The rollers should be kept clean, but should not be too moist, as this
will prevent the ink from distributing equally over them, and from
covering evenly the surface of the types or engraving; nor should they be
too dry, as in that case they will not dispose of the ink smoothly enough
to produce a fine impression, neither will they retain particles of dirt
on their surface, but it will part with them to the form, thus causing
picks.
The ink ought to be rubbed out thinly and equally on the ink-block, so
that when it is taken it may be diffused smoothly over the surface of the
rollers. It is advisable to keep rubbing the ink out on the block with
the brayer, and to distribute the roller almost constantly; the continual
friction produces a small degree of warmth, which is of advantage,
particularly in cold weather.
As uniformity of colour is requisite for beauty in printing, where the
form is large the pressman should take ink for every impression: this may
be thought troublesome, but it is advantageous in producing regularity
of colour. It is unpleasant to see in a fine book two pages that face
each other differing in colour,—the one a full black, surcharged with
ink, the other deficient in quantity and of a gray colour; yet this must
happen when, as is frequently the case, three or four sheets are printed
with one taking of ink.
In fine books, particularly where the paper is large and heavy and the
type large, set-off sheets are used to interleave the whole impression
while working: these remain till the printed paper is taken down from the
poles by the warehouseman. These set-off sheets are put in when the white
paper is working, and moved from one heap to the other during the working
of the reiteration. They prevent the ink from setting off from one sheet
to another while they are newly printed, from the weight of the paper.
To secure uniformity of impression, the pull should be so adjusted in the
first instance as to give a proper degree of pressure on the form when
the bar is pulled home; then, checking the bar, it should be allowed to
rest in that position during a short pause.
It will be perceived that, to produce presswork of a highly superior
character, great expense and much time are required; and that it is
requisite to have a good press in good condition; to have new types,
or types whose faces are not rounded by wear; to have good rollers in
good condition; that the ink should be strong, of a full black colour,
that it will not fade nor stain the paper, and ground so fine as to be
impalpable; the paper should be of the best quality, made of linen rags,
and not bleached by means of acids or bleaching powders, which have a
tendency to decompose the ink; the rolling should be carefully and well
done; the face of the type should be completely covered with ink, without
any superfluity, so as to produce a full colour; and the pull should be
so regulated as to have a slow and great pressure, and to pause at its
maximum in order to fix the ink firmly upon the paper. These particulars
observed, with nothing but paper in the tympans, perfect impressions of
the face alone of the type will be obtained, and a splendid book will be
produced in the best style of printing.[20]