DIRECT TRANSFERS TO ZINC.
We have now treated of the various stages necessary to obtain a
photographic transfer upon zinc, from a drawing or engraving, in line,
in dot, or in stipple, first by making therefrom, in the camera, a
negative—same size, reduced, or enlarged—and from that negative a print
on zinc, either in ink on an albumen basis, or in bitumen.
These transfers can be used, either for yielding re-transfers for
lithographic press, or (as is at present our intention) for etching
into relief, for use as blocks for printing from letter-press.
Before proceeding to instruction for etching these photographic
transfers into relief, we will consider the method of dealing with the
direct transfer of drawings, in line or chalk, to zinc, without the
intervention of photography.
For direct transfers to zinc, the picture is drawn by the artist
the exact dimensions of the finished block; if in line, on ordinary
lithographic writing transfer paper, in ordinary lithographic writing
ink, just in the same way that an ordinary line subject is treated for
ordinary lithography.
If the subject is in chalk, it may be drawn on a grained lithographic
stone, which is rolled up, etched, washed out, again rolled up, then
the transfer is pulled; or the picture may be drawn upon specially
prepared transfer paper, like Josz’s polygraphic transfer paper, or
other grained paper made for the purpose; or the subject may already
be on stone, as a lithograph, or it may be a copper-plate engraving,
in which case transfers are pulled and then put down upon zinc in the
ordinary way.
In making drawings on lithographic transfer paper, great care must be
taken to avoid touching the surface with the fingers, as finger-marks
will transfer and roll up black. In line work all lines must be firm
and black; no attempt must be made to get effect by using thin or pale
ink.
In chalk work, also, the drawing must be firm and strong, and the
corrections and alterations made on the transfer, not left to be done
on the stone. If the corrections or alterations are small, they may be
removed with an ink eraser, or by careful washing with turpentine, so
that all the chalk is removed; if the |52| correction be large, paste
a piece of clean transfer paper over the place, spreading the paste as
thin as possible; gum must not be used.
The drawing on transfer paper being obtained, the next step is to
transfer it to stone; then, after rolling up and proving, another
transfer is made, which is to zinc.
From an engraved copper plate a transfer is made on India or upon
Scotch transfer paper, on either a copper-plate press or a lithographic
press, and then transferred direct to the zinc.
The engraved copper plate is first of all examined to see that all the
old ink is out of the lines; if not, wash with turpentine and wipe
quite dry; then, in a piece of clean linen rag, tie up some plate
re-transfer ink; warm the copper plate, either on the hot plate or over
a Bunsen burner, until it can be barely held in the hand; then, holding
it in a piece of cloth to protect the fingers, rub in the ink tied up
in the linen rag, until sufficient is melted to well cover the surface,
taking care to see that the ink is rubbed well into the lines. Then
take a piece of clean, soft rag and wipe off the ink from the surface
of the plate carefully, so as not to remove it from the reversed lines;
this is best secured by wiping across the lines, not with them. When
the surface of the plate is quite free from ink, rub the lower part of
the palm of the hand upon a ball of whiting, and proceed to polish the
surface of the plate. Do not get too much whiting upon the hand, else
it may stick to the ink and prevent it adhering to the transfer paper.
Now place a piece of clean transfer paper (India or Scotch), a little
larger than the plate, face downward upon a piece of clean paper,
sponge the back with a damp sponge, then let it lie a few minutes, so
as to get evenly damp all through.
Now see that the press is ready. If a copper-plate press is to be used,
see that the bed is free from grit, and that the blankets are in place;
if a lithographic press is to be used, put in a stone, wipe it free
from grit, and see that the scraper is all right; remove the tympan if
of leather, but if of zinc or millboard it is all right. Now put the
inked and polished copper plate upon the stone, and the damp transfer
paper, face down, upon the copper plate; then upon the transfer paper
place a piece of printer’s blanket, turn down the tympan, or put a
piece of thin millboard over the blanket, run the bed of the press
under the scraper, turn down the lever, and, if necessary, adjust the
pressure (a good nip is necessary), then run the bed through; now raise
the lever, pull out the bed, lift the tympan and blanket, reverse
the plate, and pull |53| through again. Now gently warm the plate,
and carefully lift away the transfer paper, which should contain the
picture with every line firm and sharp; if it is not so, sufficient
pressure has not been used, or the transfer paper has been made too
damp, or sufficient ink has not been put into the lines.
The transfer, either drawn in line or in chalk, or from a plate, being
obtained, it is next transferred to a polished litho stone. Of course,
the picture can be at once transferred to the zinc which it is intended
to etch, but it will be found best to first of all transfer to stone,
then from the stone pull a transfer, and transfer that to the zinc,
so that in case of an accident during the etching another plate can
be quickly prepared. Before placing them upon the stone, the prepared
transfers should lie in a damping book until evenly damp.
Now take a polished litho stone and place it in front of a fire or
in the sun until it is quite dry, then place it upon the bed of the
press, and adjust the pressure; then place the transfer upon the stone
in such a manner that it lies without any slurring. Next place a piece
of clean paper upon the transfer, then the blanket, lower the tympan,
run in the carriage, lower the lever, and pull through; then lift the
lever, draw back the carriage, turn the stone round and pull through
again, then sponge the back of the transfer with water and pull through
again, repeating the damping, and pulling through three or four times.
Now with a wet sponge saturate the back of the transfer with water, and
lift away the paper, then wash away the composition, leaving the image
on the stone; now cover it with thick gum solution, and allow it to dry.
If more than one transfer is in hand at a time, they are trimmed as
closely as possible and pasted with very thin paste close together
upon a large piece of paper, and then all can be transferred at one
operation.
The gum upon the stone being dry, wash it off carefully with clean
water, then roll up with transfer ink. Clean away any dirt there may
be with sponge and snake stone; where the snake stone cannot be used,
a piece of pointed wood, dipped into acid gum, will clear way the
dirt. Take care to have the wet sponge handy so as to prevent the acid
spreading upon the work; now roll up as strong as possible, then etch,
by passing over water acidulated with nitric acid of such a strength
that it just slightly effervesces when the stone is touched; saturate
a sponge with the weak acidulated water and go gently over the stone,
then with another sponge charged with clean water, wash off the acid.
Now again roll up with transfer ink as strong as possible, and pull
the transfer. Chalk drawings are transferred to stone in the same way,
then etched, but the acid water is allowed to act a little longer than
for a line transfer, and after |54| washing away the etching solution,
the picture is washed out with clean turpentine, then wiped with a
sponge, gummed in, fanned dry, moistened with a wet sponge, and the
water removed. Then the image is rolled up with transfer ink, and the
transfers pulled for subsequent etching.
To transfer to zinc, take a piece of polished zinc and immerse it in
the graining bath (page 40) for about a minute; then remove it, wash
it under the tap, and rub it with soft sponge; then wipe it dry with a
soft rag, and warm the plate slightly; lay it upon a litho stone in the
press, lay the transfer (which has been lying in the damping book) upon
the zinc plate; lay upon the transfer the piece of blanket, lower the
tympan and pull through; then damp the back of the transfer, pull it
through again; then reverse the plate, dampen the back of the transfer,
pull through again; again dampen the back of the transfer, and again
pull through; now saturate the transfer with water, peel off the paper,
remove the composition, and apply with a sponge a sufficiency of a
solution of gum (thickness of cream), 5 ounces; decoction of nutgalls,
10 ounces. The decoction of nutgalls is made as directed on page 56.
Allow this to stay on the zinc for about a minute, then wash off,
cover with plain gum, fan dry, and dip a sponge in gum and rub over
the plate; now dip a soft rag into the gum, then into the etching ink
(page 57) mixed with a little cocoanut oil or mutton fat and middle
varnish, continuing the application of gum and ink until the whole of
the picture is sharp, black, and strong. Be sure and keep the plate
well covered with gum and the ink as thick as possible.
The plate is now dusted with finely powdered resin, sponged with a wet
sponge, and then is placed in the etching trough containing water and
just sufficient nitric acid to taste; in this the plate remains about
half a minute, rocking the etching trough gently all the time; now
remove the plate, wash it under the tap, rubbing gently back and front
with a sponge, then dry by gentle heat; next coat the back, edges, and
margin and portions of the front which are too large to etch away, with
thin shellac varnish. When dry proceed to etch as directed in the next
chapter.
Instead of inking up with the rag after etching with the acid gum, wash
off, then roll up with a leather roller charged with the etching ink
mixed with a little cocoanut oil, and used as stiff as it is possible
to work it, until the image has taken in all possible, damping the zinc
with a sponge directly it shows any signs of getting dry; then dampen
slightly, and repeat as above. Next immerse it in the etching bath as
before; wash well, and dry; coat the back, edges and margin on the
front with shellac varnish, when the plate will be ready for etching.
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