A single block, when imposed in a large chase, may spring out of the
chase while being inked, from the quantity of furniture about it. A good
plan is to impose it in a job-chase, and to impose this chase in a larger
one: this will cause it to lie flatter on the press and firmer in the
rolling, the large chase being secured firmly on the press by quoins and
the corner irons.
Before pulling the first impression, the workman should see that the
surface of the cut is perfectly clear from particles of dirt, and that no
pin or lump of paste is on the tympan. He ought then to pull very gently,
or he may injure some of the fine lines of the engraving.
Neither the pressure nor the impression of an engraving on wood should
be uniformly equal: if it be, the effect intended to be produced by the
artist will fail; and, instead of light, middle tint, and shade, an
impression will be produced that possesses none of them in perfection:
some parts will be too hard and black, while other parts will have
neither pressure nor colour enough, nor any of the mildness of the middle
tint, which ought to pervade a large portion of an engraving, and on
which the eye reposes after viewing the strong lights and the deep shades.
To produce the desired effect, great nicety and patience are required
in the pressman: a single thickness of thin India paper, (the best for
overlaying,) with the edges scraped down, is frequently required over
very small parts. The overlay should never be cut at the edges; but, even
where great delicacy of shape is not required, it should be torn into
the form wanted: this reduces the thickness of the edges, and causes the
additional pressure to blend with the surrounding parts As particular
parts of the impression will frequently come up too strong, and other
parts too weak, it will be necessary to take out from between the tympans
a thickness of paper and add an additional tympan-sheet, cutting away the
parts that come off too hard, and scraping down the edges. Scraping away
half the thickness of a tympan-sheet in small parts that require to be
a little lightened will improve the impression. The light parts require
little pressure; but the depths should be brought up so as to produce a
full and firm impression.
If a block be hollow on the surface, underlaying the hollow part will
bring up the impression better than overlaying it, at least so nearly
that only a thickness or two of paper will be needed as overlays. If
a block be too low, it is better to raise it to the proper height by
underlays than to use overlays; as the latter act in some measure as
blankets, and are pressed into the interstices, rendering the lines
thicker than in the engraving.
It will be necessary sometimes, when the surface of the block is very
uneven, to tear away parts of the paper in the tympan, to equalize the
impression where it is too hard.
The pressman will find it convenient to pull a few impressions, while
he is making ready, on soiled or damaged India paper. Out of these he
can cut overlays to the precise shape and size wanted, which are always
necessary when great accuracy is required in overlaying particular
portions. He should be provided with a sharp penknife and a pair of good
small scissors. A fine sharp bodkin and a needle or two, to take out
picks, are also needful; but he should be particularly careful so to use
them that he do no injury. The best way is, to draw the bodkin or needle
point cautiously in the direction of the lines.
Engravings in vignette form require great attention to keep the edges
light and clear, and in general it is necessary to scrape away one or
two thicknesses of paper in order to lighten the impression and keep
it clean: the edges being irregular and straggling, they are likely to
come off too hard. Bearers type-high placed beside the block will be
found advantageous; if they cannot be used, pieces of reglet, pasted on
the frisket in the usual way, and taking a bearing on the furniture,
must be substituted; but the high bearer is to be preferred where it
can be adopted. The bearers equalize the pressure on the surface of the
engraving, and protect the edges from the severity of the pull, which
is always injurious to the delicacy of the external lines. They also
render the subject more manageable, by enabling the pressman to add to or
diminish the pressure on particular parts, so as to produce the desired
effect.
When great delicacy of impression is required in a vignette, it will be
found beneficial, after the engraving is inked, to roll the extremities
with a small roller without ink: this will not only take away any
superfluity of ink, but will prevent picks, and give lightness and
softness to the edges, particularly where the effect of distance is
required.
If the extremities are engraved much lighter than the central parts,
underlays should be pasted on the middle of the block, which will give
a firmer impression to the central parts of the subject. It would save
trouble and aid in getting a good impression if the block were engraved a
little rounded on the face.
When highly finished engravings on wood are worked separately, woollen
cloth, however fine, should never be used for blankets, as it causes too
much impression; a sheet or two of hard smooth paper between the tympans
is better; sometimes even a piece of glazed pasteboard is used inside the
outer tympan. The parchments ought to be in good condition, stretched
tight, of a smooth surface, thin, and of regular thickness, so as to
enable the pressman to obtain an impression as nearly as possible from
the surface only of the engraved lines.
The rollers must be kept in perfect order; and the pressman should be
very particular in taking ink and inking the block. He ought to use the
best ink that can be procured.
When a wood-cut left on the press all night has become warped, lay it
on its face upon the imposing-stone, with a few thicknesses of damp
paper underneath it, and place over it the flat side of a planer, with
sufficient weight upon it: in the course of a few hours the block will be
restored to its original flatness. This method is preferable to steeping
the block in water; as the steeping swells the lines of the engraving,
and, consequently, affects the impression. To preserve the original
effect of the cut as it came from the hands of the artist, the block
should never be wet with water; and, when it has been worked in a form
with types, it should be taken out before the form is washed.
To prevent warping during the dinner-hour or the night, turn the tympan
down upon the form, run the carriage in, and, pulling the bar-handle
home, fasten it so that it will remain in this position during the
interim.
However long boxwood may be kept in the log, it will always twist and
warp when cut into slices for engraving, on account of fresh surfaces
being exposed to the air. Large blocks may be restored to their flatness
in the course of a night by laying them on a plane surface, with the
hollow side downward, without any weight on them.
A fine engraving on wood should never be brushed over with ley: the best
method is to wipe the ink off with a fine sponge damped with spirits of
turpentine, and, if it get foul in working, clean it with a soft brush
and spirits of turpentine; then wipe the surface dry and pull two or
three impressions on dry waste paper. Spirits of turpentine take off
the ink quicker, and affect the wood less, than any other article. The
facility with which the block is again brought into a working state more
than compensates for the trifling additional expense incurred.
When a few proofs only are wanted from a small engraving, good
impressions may be obtained with little trouble on dry India paper, with
about six thicknesses of the same sort of paper laid over it, and pulled
without the tympan. If proofs are wanted from large ones, it will be
found advantageous to put the India paper for a few minutes into a heap
of damp paper.
To do full justice to an engraving, the pressman should get a good
impression from the engraver and place it before him as a pattern, and
then arrange the overlays, &c. till he produce a fac-simile in effect.
Better still is it for an unpractised hand to obtain the assistance of
the artist at the press-side, to direct him in making ready the cut.[21]