How To Make A Negative Drawing
The drawing paper for designs to be reproduced by the cyantotype and the
other processes described in this book should be of a fine texture, free
from opacities and very white; and, as the design must serve as a cliche
it is a sine qua non that it be drawn with a very black ink and with
well-fed lines, especially those which are very fine. To obtain a
complete opacity, and, at the same time, to keep the ink quite fluid,
which gives great facility to the designer, one adds some gamboge (or
burnt sienna) to the India ink. The ink of Bourgeois, which is compounded
with yellow and can be diluted as easily as India ink, is excellent, so is
also the American ink of Higgins.(3)
As much as possible it is desirable to replace the colored lines
indicating the constructions, the axis, projections, etc., by differently
punctuated lines made with India ink. However, if the use of colors be
obligatory on the original design, one should trace the red lines with
very thick vermilion or sienna, the yellow lines with gamboge, and the
blue and green lines with a thick mixture of Prussian blue and chrome
yellow in different proportions.
One must abstain from applying washes of any tints on the original. If
necessary they should be brushed over when the reproductions are made;
moreover they can be often replaced by cross-lines more or less open, and
the shadowing represented by thicker but not closer lines.
Tracing paper is recommended instead of linen, which latter, on account of
its thickness and granulation, gives less satisfactory results in regard
to the transparency of the ground and the continuity of the lines.
To reproduce a design on ordinary paper--not too thick--or an engraving,
etc., the paper is rendered transparent by rubbing over on the back of the
original a solution of 3 parts in volume of castor oil in 10 parts of
alcohol, by means of a small sponge. When the paper is quite transparent,
the oil in excess is removed by pressure between sheets of blotting paper,
and the paper dried before the fire or spontaneously. The design so
treated is not in the least injured, for it assumes its primitive
condition by dissolving the oil from the paper by immersion into strong
alcohol, which it is necessary to renew once or twice, then rinsing in
alcoholized water if the drawing be in India ink, or simply in water in
the case of an engraving, and finally drying between sheets of blotting
Instead of an alcoholic solution of castor oil, vaseline can be employed.
The paper is more transparent.
The method by which are made negative drawings, that is, those which can
be used as negative cliches to reproduce the design in black lines on a
white ground, is thus described by Mr. Cheysson, wlio originated it, in a
manual published by the Department of Public Works of France, from which
we have borrowed most of the above instructions for the drawing of designs
suitable for the photo-reproduction processes:(4)
"One can avoid the necessity of making a negative from the original
drawing by transforming the drawing itself into a negative."
"To that effect it suffices to draw with lithographic ink, then to cover
the paper with aniline brown, and, after drying, to wash it with
turpentine oil which dissolves the lithographic ink without altering the
aniline. The lines appear then white on a brown ground impervious to
light (that is, non-actinic). The design is thus transformed into a
negative, and can yield positive impressions with paper sensitized with
silver salts, the ferriprussiate or the bichromate of potash. The
lithographic ink should be very black and the lines well fed."
"When the drawing is finished it is placed on a board lined with sheets of
blotting paper, then one spreads all over it the aniline brown with a
brush, and, lastly, after drying, the paper is carefully rubbed with a
bung of cotton or a rag imbued with turpentine until the lines of the
design are dissolved."
In our practice we have often taken a negative cliche from drawings made
in the ordinary manner, without the aid of the camera obscura (which would
have been too expensive for drawings of a certain size), by simply
printing a proof by contact on plain or albumenized silvered paper, and
fixing, without toning, in a new solution of sodium thiosulphate, then
washing as usual. The proofs thus obtained from designs drawn with an
opaque ink, which allows a long insulation and, therefore, yields an
intense reduction, are of a deep brick-red color, quite non-actinic, and
give very good positives by the Artigues process.
N.B.--Paper in drying never assumes its original shape; it is, therefore,
necessary to make the figures on the reproductions from plans when they
are not on the originals.