DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.20658#0354
340
AQUA-TINTA.
till the gum changes colour, when it will be sufficiently melted to adhere to the copper, then
stop up all the lights or places where there is to be no work: when cold, raise a border of wax
round the plate, and pour on the aqua-fortis, for the first tint, which is to remain on the plate
about five minutes, and then poured off, and the plate warmed and perfectly cleaned from this first
ground, by adding a little oil, if necessary : the lighter tints being finished, they must also be
stepped up, as well as the blank parts of the copper, and the second powder sifted on the plate,
the copper heated, and the aqua-fortis poured on as before, to produce the seeond tint. The
coarser powder, or rather grains of gum, must also be heated in the same manner.
The difference of the powders creates a difference of tints: for the coarser and larger the grains
are the more firmly they adhere to the copper, and their contact with the plate occupies a larger
surface; they also permit more copper to be corroded away from around them by the aqua-
fortis : but if a ground were not previously laid by the finer powders, the coarse powder would
produce very staring whites; or if the gross powder were misplaced, it would greatly disfigure
the piece. The gross powder also requires the plate to be more heated. A larger grain of white
may be produced by melting the finer powder more than usual, which makes the particles spread,
and occupy a larger surface. Sometimes a finer tint may be laid over a coarser one with very
good effect, as weil as a coarse one over a finer. In this method of working, any part of the
plate may, at any future time, be rebitten, if required, provided that the other pans are securely
stopped up ; which is very useful to the learner, as he may improve and rebite his piece to his
mind. The principal requisite is the skilful management of the varnish, which requires some
patience and experience to enable the artist to stop up the lights and lighter shades, in their
proper places; as in a good piece the different shades are very often so much mingled and
blended together. Le Prince's method is, however, certain in its operation, and generally
rewards the student who pursues it diligently.
There are several other methods of working in aqua-tinta, devised by ingenious engravers,
which do more credit to their invention, than bestow utility to art: the main process of two of
the principal I shall give, as they include the general piinciples of a numerous train.
One method is, by applying an acid capable of corroding the copper, without using aqua-
fortis : the operation is briefly this:—Mix a quantity of ground sulphur with oil, and Jay the
mixture on the copper with a pencil in the manner of painting, and in those parts of the design
yon wish to corrode : then, by placing the plate over a gentle fire, the vitriolic acid contained
in the sulphur is set at liberty, and corrodes the copper: the plate is then washed clean, and
again painted with the mixture in all the parts, except the lights and faintest tints, (which
latter have already been corroded :) it is again exposed to the fire, and made somewhat hotter
than before, which will answer the same intention as a second biting with aqua-fortis. The
plate being cold, and washed, it is to undergo another operation for the deepest shades, being
made somewhat hotter than the last time, and exposed to the fire a longer time. In this mode
of procedure, as it is observed that the acid in the sulphur acts on the copper more or less, in
proportion to the heat, and the time it is suffered to continue on the plate, it must consequently
remain longer on the oopper, and the plate heated to a greater degree for the second tint than
for the first; and still more so for the third than for the second.
This practice of etching has not been much followed, on account of the inconvenience at-
tending the operation, from the nauseous fumes of the heated sulphur; otherwise there is little
doubt
AQUA-TINTA.
till the gum changes colour, when it will be sufficiently melted to adhere to the copper, then
stop up all the lights or places where there is to be no work: when cold, raise a border of wax
round the plate, and pour on the aqua-fortis, for the first tint, which is to remain on the plate
about five minutes, and then poured off, and the plate warmed and perfectly cleaned from this first
ground, by adding a little oil, if necessary : the lighter tints being finished, they must also be
stepped up, as well as the blank parts of the copper, and the second powder sifted on the plate,
the copper heated, and the aqua-fortis poured on as before, to produce the seeond tint. The
coarser powder, or rather grains of gum, must also be heated in the same manner.
The difference of the powders creates a difference of tints: for the coarser and larger the grains
are the more firmly they adhere to the copper, and their contact with the plate occupies a larger
surface; they also permit more copper to be corroded away from around them by the aqua-
fortis : but if a ground were not previously laid by the finer powders, the coarse powder would
produce very staring whites; or if the gross powder were misplaced, it would greatly disfigure
the piece. The gross powder also requires the plate to be more heated. A larger grain of white
may be produced by melting the finer powder more than usual, which makes the particles spread,
and occupy a larger surface. Sometimes a finer tint may be laid over a coarser one with very
good effect, as weil as a coarse one over a finer. In this method of working, any part of the
plate may, at any future time, be rebitten, if required, provided that the other pans are securely
stopped up ; which is very useful to the learner, as he may improve and rebite his piece to his
mind. The principal requisite is the skilful management of the varnish, which requires some
patience and experience to enable the artist to stop up the lights and lighter shades, in their
proper places; as in a good piece the different shades are very often so much mingled and
blended together. Le Prince's method is, however, certain in its operation, and generally
rewards the student who pursues it diligently.
There are several other methods of working in aqua-tinta, devised by ingenious engravers,
which do more credit to their invention, than bestow utility to art: the main process of two of
the principal I shall give, as they include the general piinciples of a numerous train.
One method is, by applying an acid capable of corroding the copper, without using aqua-
fortis : the operation is briefly this:—Mix a quantity of ground sulphur with oil, and Jay the
mixture on the copper with a pencil in the manner of painting, and in those parts of the design
yon wish to corrode : then, by placing the plate over a gentle fire, the vitriolic acid contained
in the sulphur is set at liberty, and corrodes the copper: the plate is then washed clean, and
again painted with the mixture in all the parts, except the lights and faintest tints, (which
latter have already been corroded :) it is again exposed to the fire, and made somewhat hotter
than before, which will answer the same intention as a second biting with aqua-fortis. The
plate being cold, and washed, it is to undergo another operation for the deepest shades, being
made somewhat hotter than the last time, and exposed to the fire a longer time. In this mode
of procedure, as it is observed that the acid in the sulphur acts on the copper more or less, in
proportion to the heat, and the time it is suffered to continue on the plate, it must consequently
remain longer on the oopper, and the plate heated to a greater degree for the second tint than
for the first; and still more so for the third than for the second.
This practice of etching has not been much followed, on account of the inconvenience at-
tending the operation, from the nauseous fumes of the heated sulphur; otherwise there is little
doubt