IMPROVEMENTS IN PHOTOGRAPHIC PROCESSES, AND IN PORTRAITS OR IMAGES PRODUCED THEREBY
Year: 1864

page_text: PROVISIONAL SPECIFICATION left by Leandro Crozat at the Office of
the Commissioners of Patents, with his Petition, on the 25th November
1864.
I, LEANDRO CROZAT, of Seville, in the Kingdom of Spain, and of 53, Chancery
Lane, in the County of Middlesex, Merchant and Photographer, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN PHOTOGRAPHIC
PROCESSES, AND IN PORTRAITS OR IMAGES PRODUCED THEREBY," to be as follows:-
In order to produce photographs in what I call double ground on my system
the sitter should be placed before a white cloth, three feet square, the ground
of which should be colored in distemper, and graduated or shaded, the cloth
being supported by a head rest when the negative is taken in the ordinary.
way, which negative being freely exposed to the sun produces the portrait.
If I wish to produce a shaded bust terminated in white, I act in the
following manner :-I take the plate and apply a small piece of paper to the
side that is not collodionized, and trace with a pencil the size which the bust
should have, then cut out the line so traced by the pencil so as to mark easily
the same outline on a piece of stiff opaque cardboard of the size of the
pressure frame glass. Place this cardboard in the pressure frame, then the
glass, which should be of the ordinary thickness in order that it may produce.
a fine shading, then place the plate so that it should be opposite the bust. cut
out on the card, as it is through this that the light is admitted... Two small.
pieces of gummed paper will support the plate against the glass of the pressure:

page_text: frame by its two opposite angles, in order that the plate and the cut-out part
of the card may be always in the same position. All the proofs taken may be
of one size and have the same shading or gradation. Lastly, glue before the card
on the pressure frame a small piece of thin and slightly azured paper, and in
this position, after having placed the nitrate paper on the plate expose it to
the sun in order that it may produce the shaded bust.
I have adopted this system for the shaded busts because the system of
yellow glasses throws out an oval shading or gradation which is sometimes out
of proportion and always rising in the shape of a pyramid surrounding the.
head in opposition to the rules of art, which prescribe that the shade should
only surround the body, such as is seen in the best engravings. I have now
obtained the shading ground.
To obtain the general ground a glass should be procured, painted on the
back with white pastile paint, or, if preferred the desired inscription, by means
of a tracing made by a lithographer. Stick a proof taken with any nitrate paper
on yellow or green strong paper; let it dry a little, then cut out the head and
the white part of the bust, and this silhouette is lightly stuck on the glass on
the side of the inscription. Then continue applying the white ground portraits
on the glass so that the head perfectly covers the silhouette, and this in its
turn should entirely cover the whole of the shirt front, and by thus supporting
the portrait with a tablet of the same size as the card, expose it to the sun for
twelve, fourteen, sixteen, or eighteen seconds, according to the light and the
activity of the nitrate paper. The second ground is thus obtained.
It is well understood that the silhouette must be cut out a little shorter
on the side of the hair and with great exactitude on the side of the face; it
should be a little wider on the side of the whites, which is done by making
the scissors run on the black, but the face is to be cut out exactly by following
the line. If any hairs should project either from the head or from the beard
they must be cut off. The double ground once obtained, it must be toned and
fixed by the ordinary method, which will be treated of hereafter. When the
portrait is dry cover the eyes and the shirt front with some diluted 'gum
arabic in order to preserve them from the coloring which is to be applied to
the whole face, leaving it a moment to allow the gum to dry.
The instantaneous coloring is obtained in the following manner: -Dip a
brush of the size of a pen into the liquid called the instantaneous coloring,
the component parts of which are given hereafter, and pass it successively on
the lips of the portrait; then take the first and pass the brush on the most
shaded cheek by rubbing and enlarging the circle which is to be. colored; then

page_text: pass it in the same way on the extremity of the chin and then on the cheek.
that is less shaded; lastly on the whole face. All these operations must be
performed quickly in five or six seconds, or else the picture takes too much
color and does not succeed. Then put the portrait into a basin of water, and
pass over it two or three times a very soft brush to remove the gum and the
superfluous color; this done, place it twice in succession between folds of
blotting paper, pressing your hands over it in order to dry it. The operation
of coloring the first of the three portraits being over, take a fourth portrait
and touch its lips with the brush, and leave it to return to the second portrait.
of the first three; as the legs have already been colored, pass the brush on the
cheeks, on the chin, and on the whole face, washing and drying it as explained
for the first portrait. Take a fifth portrait; touch the lips with the brush;
leave it, and return to the third of the first three, and repeat the same
operation as on the first and second. By acting thus you will always have
three portraits with their lips colored and ready for the complete coloring of
the face.
However, either from want of practice or some other reason, some may
prefer a weaker coloring in order to be able to paint with greater ease but less
rapidly; in this case they have only to double or triple the quantity of water
without altering the proportions of the components.
When colored, the portraits will still require greater brilliancy. For this
purpose I take a glass rather larger than the portrait, and pour over it, as if
to colodionize it, the solution No. 1 of the preservative varnish herein-after
given, and one minute after put the glass thus prepared into a porcelain pan
containing the solution No. 2, and with a hook raise it a little from time to
time until it is slightly covered with the liquid, which will be seen by the
cessation of the veins or tears noticeable on the coating of the first solution ;
then take out the glass and leave it on the table; take the portrait and place
it
on the blotting paper and the picture downwards; pass on the back of
this portrait a soft brush imbibed with water in order to soak it well; shortly
after stretch it on the prepared glass by slightly passing your fingers over it
to make it adhere evenly, and allow it to dry, which will take more or less
time according to the atmosphere of the place. In damp weather I varnish
in the operating room at night, and the portraits are detached in the morning;
in summer. I detach, them half an hour after varnishing, and sometimes
sooner. In order to detach the portrait from the glass pass the blade of a
penknife or a similar instrument up and down on each side, then taking the
portrait and lifting it by one corner it may be completely separated from the

page_text: crystal, but if the portrait should not come off properly it is a proof that the
glass was not clean, in which case it will be sufficient to breathe on it for a
few moments or to expose it to the influence of steam. Once detached, the
portrait should be cut out and stuck on the cardboard with a thick solution
of gum arabic.
In order to render a glass fit to receive the varnish it should be cleaned as
follows-Place it in a solution of nitric acid in the proportion of one part of
neid to two of water. At the end of twenty or thirty minutes wash it with
water, wipe it with a piece of linen, and place it on the tablet called plate
cleaner or polisher, and rub it with a piece of bombazine containing some
powdered Briançhon chalk (glove or boot powder) and then pass over it a
soft haired brush. As in winter it will happen that the solution No. 2 or
gelatine may become chilled or coagulated, to keep it lukewarm I use a tin
box on which I place the basin containing the gelatine, and inside the box is
a small spirit of wine lamp with but very little flame. By using two or three
basins at a time two men can easily varnish two hundred portraits in one hour,
by using glasses large enough to hold four or more portraits they could
varnish a much larger number. Images other than portraits may be produced
in like manner.

page_text: PRESERVATIVE VARNISH:-1ST SOLUTION.
Sulphuric ether at 60 degrees
Alcohol at 40 degrees
Photographic cotton
34 cubic inches.
28 cubic inches.
from 30 to 35 gr.,
according to its greater or less facility of dissolving.
Observations. The ingredients above mentioned are put into a bottle in
the prescribed order, and are to be agitated until in perfect solution. This
solution should only be used after 24 hours settling; it is still better if it
is let stand longer.