A technical dictionary of
printmaking, André Béguin.
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Etching Ground
In Abraham Bosse's treatise as corrected by Cochin in 1745
the latter points out that he knows of two different
grounds. The first has "the consistency of a very greasy oil
or of a transparent syrup of a reddish colour. When it is
applied to the plate and is left to dry it becomes hard.
Thus it may be called a hard ground." The second type of
ground "when cold has more or less the consistency of pitch
or black wax. When it is put onto the plate it only needs to
be blackened or whitened. It does not need to dry as it will
keep its sof ness and because of this it may be called a
soft ground ". Each of these two grounds was used with a
different mordant.
The hard ground was usually made with five ounces of greek
pitch (Perrot in 1840 speaks of 120g) which can be
substituted with Burgundy fatty pitch, to which was added
five ounces of Tyre resin known as colophony (150g) or a
common resin if the colophony was not available. These
ingredients were then melted together on a low fire and in a
glazed pot. Once they had melted one added four ounces of
walnut oil ( 120g) or some linseed oil. The mixture was then
heated for half an hour. When the ingredients began to
coagulate and became like a gluey sirup it was fitered
through some cloth.
Jacques Callot had told Bosse that he had his hard ground
come from Italy ready made. It was a varnish used by cabinet
makers which in Italy was called "vernice grosso da
lignaioly". This varnish was a specialty of Venice and
Florence where it could be bought in the shops of drug and
spice merchants. The ingredients and preparation of this
florentine varnish consisted in heating some fatty
and clear linseed oil (Perrot calls for 1209) to which one
then added the same amount (120g) of pulverized mastic
drops. The whole was then mixed until perfectly blended and
when this was accomplished the mixture was filtered through
a piece of cloth into a wide-necked bottle.
The soft
ground was made
of five and a half ounces (somewhat more in winter) of
virgin white wax (Perrot calls for 50 g), one ounce of
mastic drops (30g), and half an ounce of calcified spalt
(15g of Syrian asphalt). The spalt and the mastic had to be
ground finely but separately. Then the wax was melted in a
glazed earthenware pot. When the wax was hot one dusted into
it the mastic powder while continously stirring. Next the
asphalt was dusted into the mixture and the whole was
stirred for another quarter of an hour. When all this was
done the mixture was poured into a platter full of clean
water and kneaded in the water. The kneading was done to
obtain a roll about one inch in thickness from which were
made little balls which were then wrapped up in pieces of
taffeta cloth.
The hard ground and the soft ground were used for different
purposes for a long time. Hard ground was used for results
resembling line engraving while the soft ground was used for
artist's engravings [*
engraving].
As of the end of the 17th century only the soft ground was
used and today only more or less soft grounds are in
use.
The ancient recipes written up by Bosse and Cochin are as
follows:
Rembrandt's ground: 30g of virgin wax, 15g of mastic
drops, 25g of asphaltum or amber.
Ground discovered in a manuscript of Callot: 60g of
virgin wax, 6Og of amber or Syrian asphalt, 30g of resin,
60g of mastic drops, SOg of Burgundy pitch, and 15g of
turpentine oil.
Soft ground "translated from an English book" : 120g
of virgin wax, 6Og of asphaltum, 3Og of amber, 30g of mastic
drops (this ground is for summer use but must not be heated
too much).
"An excellent ground which several Parisian engravers use
at present": 30g of virgin wax, 30g of asphaltum or
greek pitch, 15 g of black pitch, and 7.5 g of Burgundy
pitch.
"M.T. 's ground" 75g of virgin wax, 90g of Burgundy
pitch, 15g of resin, 60g of Syrian asphalt, and 15g of
turpentine.
Another soft ground: 60g of virgin wax, 60g of
asphalt or amber, 30g of black pitch, 15g of Burgundy
pitch.
The ground used by a "very clever modern etcher": 6Og
of virgin wax, 15g of black pitch, and 15g of Burgundy
pitch.
All of these grounds (which
have the same ingredients but in different proportions) are
black ball grounds or semi-liquid ones which are laid on a
hot plate. The ball grounds are applied using a
dabber*
while the semi-liquid ones may be laid using a brush or a
roller. Since the times in which these grounds were used new
recipes have been invented, such as Perrot's ball ground
which was much appreciated in his times. This ground was
made with 120g of virgin wax, 8g of mastic drops, 60g of
Burgundy pitch, 120g of Syrian asphalt, and 4g of
concentrated rubber solution. After having ground the
Burgundy pitch and the mastic to the consistency of dust
they were mixed and melted in a glazed earthenware container
until they became liquid. Then the wax was mixed in, bit by
bit, stirring with an iron spatula and reducing the heat.
While carrying out the abovementioned procedure the Syrian
asphalt was heated in another container to which was added
the wax and resin. The rubber solution was mixed in at the
very end when the other ingredients were already perfectly
melted down. The mixture was finally poured into moulds. One
may also distill the products dissolved in oil of
turpentine. The result is heated for a quarter of an hour
and then poured into hot water and worked in order to form
balls.
In order to make a soft ground for crayon manner work
one can use a black ball ground mixed with some vaseline,
tallow, or other fatty components [
crayon manner].
The grounds or varnishes applied with a brush are
more liquid than the ball ground and can be applied when
cold but must be worked immediately since otherwise they
will flake off when drawn upon with a point. This type of
varnish is used for quick work and rebiting. The following
are the ingredients for three such acid resists:
|
I
|
II
|
III
|
virgin wax
|
10 to 15 g
|
60g
|
90g
|
Syrian
asphalt
|
30g
|
60g
|
120g
|
Greek pitch
|
|
30g
|
|
Burgundy
pitch
|
|
|
60g
|
mastic drops
|
|
30g
|
|
oil of
turpentine
|
250g
|
enough to
dilute
|
enough to
dilute
|
The abovementioned grounds
must be prepared in a double*
boiler after
having been ground thoroughly.
If an etcher wishes to bite his plate a second time or
several times he must use another type of acid resist. Since
this resist is applied with a roller (so that it will not
enter the lines) the French call it roller varnish ("vernis
au rouleau"). Roller varnish has the consistency of honey in
summer so that it will not run into the lines. It needs to
be dried for 24 hours and is not very resistant. In ball
form it is white and in liquid form it is transparent, thus
allowing the etcher to see the drawing through it. This
varnish must be applied on a hot plate. One can also use an
ordinary ball ground dissolved in some lavender oil.
Yet another resist is used to protect the back, sides, and
margins of a plate. This acid resistant varnish is used only
for this purpose. The following are the ingredients for two
such acid resists:
|
I
|
II
|
Syrian
asphalt
|
30 g
|
15g
|
oil of
turpentine
|
240g
|
240g
|
virgin wax
|
15g
|
4g
|
mastic drops
|
|
4g
|
copal
|
|
4g
|
A stoppinq
out varnish is
used to interrupt the biting on selected parts of the plate.
Bosse used some hot olive oil to which he added some candle
tallow and then boiled the mixture for an hour. However, he
also had another and easier way of making stopping out
varnish: mix one part wax, one part turpentine, one part
olive oil, and one part lard and then boil the whole
mixture. The following are some more recent recipes:
|
I
|
II
|
III
|
virgin wax
|
60g
|
30g
|
8g
|
Syrian
asphalt
|
60g
|
45g
|
30g
|
mastic in
drops
|
60g
|
|
4g
|
oil of
turpentine
|
500g
|
240g
|
240g
|
Perrot came up with a
stopping out varnish reputed to be more workable: 100g of
Syrian asphalt, l0g of melted but not decomposed succin
(yellow amber), 32g of virgin wax, 25g of mastic, 500g of
turpentine oil, and 4g of concentrated rubber solution.
Venice varnish is also used for some purposes and is
made by dissolving venitian turpentine in turpentine oil. It
is much the same as the varnish used in painting.
Alcohol varnish is used for retouching plates since
it dries rapidly but its drawback is that it tends to
flake.
All of the grounds and acid resists mentioned in this
article are also commercially made and are sold ready for
use.
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