Evaluation: The printer needs to evaluate his or her image on stone
for both the grease content of the drawing materials and the intention
of the artist. If the drawing materials contain little or no grease,
the etches need to be weak. If the drawn image is exceedingly
greasy, the image needs to be given a strong etch. The quality of the stone itself can also play a role
in evaluation. Bluish gray stones are harder and denser than yellow/white
stones. Accordingly, a blue stone can be etched with a stronger etch
without undercutting the image. Yellow/white stones may require a strong
etch to keep greasy areas from filling in while requiring an exceptionally
weak etch indelicate areas. A chart is provided below showing the general principles
involved. Drawings done with relatively greaseless materials: Number five Korn’s crayons and Stone’s crayons from
number five through seven have little grease in them. They are dominated
by hard wax such as carnauba and have other materials in them to make
them easier to wash out. Prismacolor, graphite, and even cont’e crayons
can be made to print but were never developed with printing in mind. Liquid drawing materials such as shellac, Liquitex medium, Xerox toner, and India ink can be made to print. Their etches need to be mild or weak and treatment may vary from the normal when initially printing. Light drawing middle value dark drawing
Grease bearing drawing materials: Crayons below number five include increasing amounts
of grease and other softening materials. Soap is present in Korn’s crayons
and those of some other manufacturers. Stone’s crayons are entirely
wax, but similarly, are numbered so that the softer greasier crayons
have lower numbers. The goal of the printer is to match the grease content
of the drawing materials with the etch to achieve
a balance state in which the drawing holds its value structure. Of course,
the printer may interpret the drawing favoring an area so that it becomes
darker, or deliberately etching another area so that it becomes lighter,
or so more contrast is obtained. Under etching promotes darkening of
an image. Over etching reduces details in the lightest areas and creates
more open areas free of ink. Nitric Acid and gum Arabic are the basic components
of etches used for grease bearing drawing materials. Gum Arabic is a
water-loving (hydrophilic) material from the sap of Acacia trees. It
is a long organic molecule that ends with a carboxyl radical. This is
an acid like ending to a molecule that attracts and absorbs water. The
carboxyl group is the same chemical means of attachment that binds grease
to limestone. For simplicity’s sake, the carboxyl group may be considered
jaws, and the attachment of gum to the stone
similar to an locked onto its prey. The role of acids in etching a stone
is to add strength to those jaws…or teeth to its mouth. A Basic Table: All ecthes are expressed in terms of drops of Nitric
per ounce of gum Arabic. WATER WASHES
Washes made with Stones tusche are able to take stronger
etches than their counter parts. They are prone to reticulate at almost
any saturation. Students should be careful when applying multiple layers
of tusche to consider that the grease content may be accumulating faster
than the pigment. SOLVENT WASHES Tusche washes mixed with
lithotine ( paint thinner or mineral spirits)
should assume there is a base of grease which must be broken through
in all areas. That is, the reticulation (breaking into thick and thin
deposits) that is characteristic of washes made with water, does not
hold for solvent washes. Tusche washes made with
alcohol: Reticulation will occur, but the grease conent is elatively
weak. Etches need to be adjusted accordingly. Tusche washes made with
lacquer thinner: Toxicity should dissuade students from using this
approach. The grease content is distributed evenly, but weakened. Tusche washes mixed with
both water and solvent: A wide range of appearances can be made
through exploiting compound mixtures. The results are difficult to predict
and may require decisions o be made as the stone is rolled up. STABILIZING THE STONE One etch is not sufficient to stabilize a stone.
The standard approach requires three etches with additional etches during
editioning. The additional etches will be less and less necessary as
printing continues because the stone becomes increasingly stable unless
influenced by temperature change, ink consistency, or other outside
factors. Gum massage with pure gum occasionally is helpful and allowing
an etch to rest is important. Students need to realize
that gum is not only absorbed by stones, it is also chemically
bound to the stone by “adsorbtion.”
Etch the stone: Keep the etch
stirred at all times (acid is heavier than gum and settles to the bottom). Pour the etch on the
border of the stone and work it with your hands to the center. Never
pour the etch directly onto the drawing — it's a quick way to get
etch marks in your drawing that will never disappear. After you have worked the etch
around on the stone for a couple of minutes, soak up the excess with
a gum sponge and buff the etch dry with a cheesecloth. It is important
to work fast and to keep flipping the cheesecloth to expose a dry section. Use small circular motions and just a little
more pressure than the weight of your hand. Fan the etch dry for a few minutes. It is important
that the etch be completely dry before proceeding.
If the etch is damp, parts of the image may not roll up properly
or some areas of the stone may be insufficiently etched. It is best
to let stone sit overnight at this point. Washout the drawing with Lithotine
or paste wax: Use plenty of lithotine or paste
wax and paper towels until all of the crayon
has been removed. After the drawing is washed out, rub the stone
up with printing base or leave in paste wax. This gives the stone a grease base that the
roll up ink will adhere to. It
doesn't take very much grease. All that is needed is a thin coat. The printing base should be applied to the stone
and moved around with a paper towel pad until the image is covered.
The film of grease/wax should then be buffed down with a clean paper
towel. Fan the printing base dry for a couple of minutes. You are now ready to roll up the stone with ink.
For this you will need the following: a. Leather roller and
a rolled out slab of ink. (I
recommend Senefelder’s crayon black as roll up ink - it is the stiffest
and will give you the best results. Never use color ink for a roll up.)
b. Roll of paper towels. With a roller and slab ready - along with your
sponges and water - wash the gum etch off with water. Use a pad of towels
for this first step — the printing base / wax is on top of the stone
and will get sponges very dirty - paper towels you can throw away, sponges
get expensive. Sponge the stone with water - use two sponges (1
coarse grained and 1 fine grained) carry the most water in the coarse
sponge and have the fine one as dry as you can get it.
The idea is to get the stone wet with the coarse one and then
slick down as much water as you can with the fine one.
There should be no standing water on the stone...just a thin
film. Roll ink on the stone with the roller. This will be done in steps. It is impossible to get the stone completely
rolled up with one application of ink. You must alternate between sponging
the stone with water and rolling it with a charged roller until the
image is full. Be careful not to let the stone dry - if this happens,
all of the stone will take ink, not just your drawing. For most normal
crayon drawings you will probably have to charge your roller and roll
on the stone about 6-10 times. These
are called passes (i.e., it takes 6-10 passes to roll up a stone for
the second etch). After the image is rolled up well, sponge it down
to a slick water film and fan the stone dry. Rosin the stone - procedure is same as in step
#l for the same reasons - the only difference being, the rosin is now
sticking to ink, not crayon. Talc the stone.
Same as step #2 - be sure to buff with
a paper towel. Prepare your second etch. For most crayon drawings
a second etch of 10 drops of Nitric to I oz. gum arable will be sufficient.
Be sure to keep it stirred and to start it in the border and
work it towards the center as in step #4. Buff the stone dry with cheesecloth it as in step
#5. Fan the etch dry. It is
preferred at this time to let the stone sit overnight. This allows the
gum to dry really well and to bond with the stone; however, if you are
in a rush, let it sit for at least 15 minutes, then proceed. At this point the stone should be taken to the
press and the press set up to get ready to print. This next procedure
is very important for it is the one that stabilizes the image on the
stone so that no matter what color or how many prints you wish to pull,
the image will remain the same. (1) Take the leather roller, and without adding
ink, roll it out on the glass slab until you have only the ink that
was on the roller rolled out. (2) Set the pressure of
the press to very light, so that the scraper bar just touches the stone
and you can feel a little pressure on the bar.
Be sure the stone is centered and the scraper bar is the correct
size. (3) Tear about 20 sheets of newsprint to the same
size as the stone. (4) Get your sponges and pans of water ready. (5) Scrape some Senefelder's
Crayon Black out of the can and work it up with an ink knife next to
your slab. Do not add any to
the slab at this time. (6) Wash the image out with lithotine
as in step #7. (7) Rub up with printing base as in Step #8. (8) Fan printing base dry. (9) Wash the gum off with water, as in Step #ll. (10) Sponge the stone, and slick down water film. (11) Roll on the stone with your roller that has
very little ink on it. Return
to the ink slab at least once (visit) and charge your roller. Change the pattern of your inking to place heavy
deposits where thin deposits had gone earlier. (12) After you have rolled on the stone, pull a
newsprint proof. The image will
be very light as it should be. What
you are doing at this time is getting the stone used to ink and water
at the same time, without overdoing it with the ink and thus causing
the stone to fill in. (13) Pull another newsprint proof - but this time increase the pressure a little bit. This time the
print should be a little darker. (14) Add a little ink to your slab, and give the
stone 2 visits. (15) Pull a newsprint proof. Do not add pressure. (16) Do not add ink — roll up stone - 2 visits. (17) Add some pressure and pull newsprint proof.
As you can see, you are alternating between adding ink and adding
pressure. What you hope to achieve is a set of newsprint
proofs that range from very light to fully inked print in very gradual
steps. After you have pulled a few newsprints, it will probably be necessary
to go to more than 2 visits to get the image up to its full richness
in the dark areas. (18) After the image is fully inked, add some ink
to the slab and roll it up just as you did to pull the last print. This
makes sure the stone is fully inked for the third etch. (19) Rosin and talc the stone. (20) Give the stone a third etch
- the same etch strength as the second is usually good. Areas that became
too dark quickly should be spot etched with 17 drops of nitric per ounce
of gum. (21) Buff the etch down
with a cheesecloth. (22) Fan dry and let the stone sit for awhile —
overnight is once again the best procedure at this time. The stone is now completely ready to print in any
color. |