A Process for the Reproduction of Objects, either in Relief or in Intaglio, with the Aid of Photography.
Year: 1894

page_text: Date of Application, 13th Feb., 1894
Complete Specification Left, 13th Nov., 1894-Accepted, 9th Feb., 1895
PROVISIONAL SPECIFICATION.
A Process for the Reproduction of Objects, either in Relief or in
Intaglio, with the Aid of Photography.
We, MARIO Russo, of 97 Via Pedacchia, Rome, Doctor, and GIOVANNI
BATTISTA ZANARDO, of 154, Via Sicilia, Villa Ludovisi, Rome, do hereby declare
the nature of this invention to be as follows:-
This invention has reference to a process wherein the action of suitable light
such as solar light or electric light on chemical preparations is employed in the
production in relief or in intaglio of objects of various kinds capable of being
photographed; and whereby reliefs and intaglios can be produced whereof the
various parts will be more or less prominent according to the relative prominence
or representation of prominence of the corresponding parts in the originals and
quite irrespective of the color or colors of the various parts of the originals.
For this purpose a sensitive plate suitably prepared and having juxtaposed a
negative such as hereinafter referred to as a composite negative is exposed to light,
after which the said plate is placed in a bath in which the parts that have been
acted upon by light are caused to form reliefs and hollows which are more or less
pronounced according to the quantity of light which has passed through the
composite negative; from the plate so treated moulds are made of suitable
material, such as plaster of Paris for example, wherein bas-reliefs, in metal or
other material can be produced either by electrotyping, or by fusion, or by other
known or suitable process.
The principal object of this invention is to obtain the proper relative relief of
the various parts of any subject independently of their color and this is attained
by the use of the composite transparent negatives each of which comprises a
transparent negative taken from the object of which a representation in relief or in
intaglio is required in conjunction with a transparent positive (taken from the
negative) on a celluloid pellicle.
The negative and positive forming the said composite negative are employed,
one arranged over the other, in such a manner as to make all their details
correspond almost exactly. This superposition, which must be sufficiently delicate,
should be done in such a manner as not to neutralize the tints but to produce the
effect of a negative taken from an object of a single colour.
It is necessary that the negative be very clear and exact in all its details
and that in it the more prominent parts be the better illuminated. Also the
negative should be strongly developed but without having its transparency
impaired.
We will now describe the process of preparing the sensitive plates, which we
prefer.
We commence by preparing sheets or plates of gelatine in the following
manner.
We take of white gelatine 100 grammes which we soften in 400 grammes of
water and afterwards dissolve in a water-bath heated to a temperature not
exceeding 45° C.
We add pure glycerine 35 grammes and add 15 grammes of ammonia and stir
gently preferably with a glass rod.
When this solution is nearly cool but still capable of flowing, we pour it gently
so as to form a thickness of about 5 millimetres of the composition, over well
.מ
037

page_text: polished glasses which are covered with talc and surrounded by a border or frame
and we allow them to dry as rapidly as possible. When the solution thus prepared
is well dried we detach it from the glasses in the form of sheets or plates of gelatine
and preserve them between sheets of paper.
Proceeding to the preparation of the sensitive plates proper we prepare
bichromated gelatine by heating and mixing in a water-bath; very pure gelatine
4 grammes, distilled water 100 grammes, bichromate of ammonium 1 gramme and
filter the resultant.
We then take a plate of glass finely ground on one side, over which side we
spread with a brush or spoon an appropriate quantity of bichromated gelatine and
then place, very carefully over the said layer a sheet of dry gelatine prepared as
before mentioned, taking care that no air bubbles remain between the glass and
the sheet of gelatine. This being done we spread over the dry gelatine a coating
of the bichromated gelatine allowing it to flow over the sheet in such a manner as
to form a perfectly level and smooth surface. We then allow it to dry in a place
protected from the dust. This operation should always be performed in a place
from which natural light is excluded or is only obtained through red or orange
glass or if artificial light is used a lamp or candle protected by red or orange
glass as is usual in a photographic dark room.
The sensitive plate which must be carefully kept shielded from light and
dust is now ready to receive the impression, which is effected in the following
manner.
To the sensitive plate we juxtapose the composite negative that has been
hereinbefore described care being taken that the positive transparent pellicle be
in perfect contact with the sensitive plate; then expose to the light.
The following table indicates the approximate appropriate duration of the
Electric light.
exposure.
Sun.
3 to 4 hours.
Diffused light.
6 to 8 hours.
5 to 6 hours.
After the exposure to this light we proceed to the development. We allow
the sensitive gelatine plate to cool if it has been exposed to the sun, then we
immerse it in a suitable basin of water moving it frequently until it presents the
requisite relief.
We then remove it from the water and leave it during some hours in a 5% solution
of sulphate of iron. On removing from this bath and having been washed, the
ladih sinfinuator in furnish the mould necessary for the production
COMPLETE SPECIFICATION.
A. Process for the Reproduction of Objects, either in Relief or in
Intaglio, with the Aid of Photography.
We, MARIO Russo, of 97 Via Pedacchia, Rome, Doctor, and GIOVANNI
BATTISTA ZANARDO, of 154, Via Sicilia, Villa Ludovisi, Rome, do hereby
declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement :-
This invention has reference to a process wherein the action of suitable light

page_text: such as solar light or electric light on chemical preparations is employed in the
production in relief or in intaglio of objects of various kinds capable of being
photographed; and whereby reliefs and intaglios can be produced whereof the
various parts will be more or less prominent according to the relative prominence
or representation of prominence of the corresponding parts in the originals
and quite irrespective of the color or colors of the various parts of the
originals.
In carrying out this process we first obtain a negative of the object to be
reproduced in relief and from this negative we make a transparent positive of
approximately the same density. It is necessary that the negative be very clear
and exact in all its details and in it the more prominent parts be the better
illuminated. The negative should also be strongly developed but without having
its transparency impaired.
Having obtained a suitable negative and positive, we proceed to the preparation
of a sensitive plate which is made in the following manner; we first prepare sheets
or plates of non-sensitized gelatin as follows: We take of white gelatin
one hundred grammes which we soften in four hundred grammes of water and
afterward dissolve in a water bath heated to a temperature not exceeding
45° Centigrade. To the solution we add thirty five grammes of pure glycerine
and fifteen grammes of ammonia and the whole stir gently, preferably with a glass
rod. When this solution is nearly cool but still capable of flowing, we pour it
gently, so as to form a thickness of about five millimetres of the composition,
over well polished glasses which are covered with tale and surrounded by a border
or frame and we allow the sheets thus formed to dry as rapidly as possible. When
the-sheets thus prepared are well dried we detach them from the glasses in the
form of sheets or plates of gelatin and preserve them between sheets of paper.
These plates thus prepared will keep indefinitely and a stock of them may
conveniently be prepared and kept ready for use.
When it is desired to prepare a relief we make a sensitized plate in the following
manner; We first prepare bichromated gelatin by heating and mixing in a water
bath four grammes of very pure gelatin, one hundred grammes of distilled water;
and one gramme of bichromate of ammonia and filter the resulting mixture. We
then spread the bichromated gelatin thus prepared, in an even layer over the
surface of a finely ground plate of glass on the ground side. By using ground
glass the gelatin firmly adheres to the surface of the plate and will not become
detached, when the plate is immersed in water for swelling, as would be the case if a
polished surface were employed. We then place upon this layer, very carefully,
one of the sheets of dry gelatin prepared as above mentioned, taking care that no
air bubbles remain between the glass and the sheet of gelatin. This being done
we spread over the dry gelatin a coating of the bichromated gelatin, allowing it
to flow over the sheets in such a manner as to form a perfectly level and smooth
surface. We then allow it to dry in a place protected from light and dust. This
operation should always be performed in a place from which natural light is
excluded or is only admitted through red or orange glass; or if artificial light is
used a lamp or candle is employed protected by red or orange glass, as is usual in a
photographic dark room. The sensitive plate, which must be carefully kept
shielded from light and dust, is now ready to receive the impression which is effected
in the following manner. We superimpose upon the sensitive plate thus prepared,
a negative and positive produced as before mentioned, in such a way that the
details shall almost, but not exactly, correspond or register. We then clamp the
negative, positive and sensitized plate together and expose to the light. The
following indicates the approximate duration of exposure: sun, three to four hours;
diffused light, six to eight hours; electric light, five to six hours.
The purpose of placing the negative and positive slightly out of register is this;
If a negative and a positive of substantially the same density be exactly super-
imposed, one over the other, the result is that the transparent parts of the negative
will be blocked by the opaque parts of the positive so as to present a practically

page_text: even opaque appearance, but if the position of one of the plates be shifted slightly
so as to have the details of one slightly out of register with those of the other, it
will be noticed that there is at once produced a relief effect and it is this fact that
we take advantage of. By using a negative and a positive of substantially the
same density, the difference of colors is practically eliminated because the color
effect of the negative almost counteracts the color effect of the positive.
After the plate has been exposed as before stated, we proceed to the development,
first allowing the sensitive gelatin plate to cool if it has been exposed to the sun.
The developing is effected by immersing the plate in water and moving it frequently
until it presents the desired relief. If the plate be immersed for a comparatively
short time, the relief will be slight; if it be immersed for a longer time the relief
produced will be greater, and we may take advantage of this fact to regulate the
amount of relief according to the subject, or the effect desired to be produced.
When the desired relief has been obtained we remove the plate from the water and
immerse it for several hours in a five per cent. solution of sulphate of iron or other
hardening agent; we then remove it from this bath and thoroughly wash it, after
which it is ready for use to produce the mold from which reliefs may be produced
by electrotyping, or by any other process, in the usual manner.
In cases where the larger part of the figure to be reproduced is of a uniform
light colour, that is to say, where there are only one or more transparent spots in
the negative which are to be rendered opaque, we have found it advantageous to
only apply to the negative the parts of the positive corresponding to such portions
of the negative as are to be rendered opaque.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The herein described process of reproducing objects in relief or in intaglio,
whereby there is obtained the proper relative relief of the various parts of any
subject irrespective of its color or colors, the same consisting in first superposing
upon an ordinary negative a positive, or part of a positive, as described so as to
be slightly out of register, and in contact with a suitably prepared sensitive plate,
then exposing the plate thus arranged to light, then subjecting said sensitive plate
to a bath of water substantially as described.
2. The process herein described of reproducing objects in relief or in intaglio,
whereby there is obtained the proper relative relief to the various parts of any
subject irrespective of its color or colors, the same consisting in the first
superposing upon an ordinary negative a positive, or part of a positive, as described,
so as to be slightly out of register, and in contact with a suitably prepared
sensitive plate, then exposing the plate thus arranged to light, and then subjectin
said sensitive plate to a bath of water and then to a hardening bath, .substantially
as set forth.
3. The process herein described of reproducing objects in relief or in intaglio,
whereby there is obtained the proper relative relief to the various parts of any
subject irrespective of its color or colors, the same consisting in first superposing
upon an ordinary negative a positive, or part of a positive, as described, so as to
be slightly out of register, and in contact with a suitably prepared sensitive plate,
then exposing the plate thus arranged to light then subjecting said sensitive plate
to a bath of water, then to a hardening bath, and then making from the said plate
a mold of plastic material, substantially as set forth.
4. The process herein described of reproducing objects in relief or in intaglio,
whereby there is obtained the proper relative relief of the various parts of any
subject irrespective of its color or colors, the same consisting in first superposing
upon an ordinary negative, a positive, or part of a positive, as described, so
as to be slightly out of register, and in contact with a suitably prepared sensitive
plate, then exposing the plate thus arranged to light, then subjecting said sensitive
plate to a bath of water, then to a hardening bath, then making from the said plate

page_text: a mold of plastic material, and finally making a relief from said mold, substantially
as set forth.
5. The process herein described of preparing sensitive plates for use in the
production of objects in relief or in intaglio, the same consisting in first applying
to the ground surface of a glass plate a coating of bichromated gelatin prepared as
explained, then applying to the surface thus coated a layer or sheet of dry gelatin
prepared as explained, and finally spreading over the surface of the dry gelatin layer
a coating of the bichromated gelatin, substantially as set forth.
6. In a process of reproducing objects in relief or intaglio, the sub-process which
consists in superimposing a negative upon a positive in such a manner that the details
are slightly out of register, and then submitting a sensitive plate to the action of
light through the so arranged positive and negative, substantially as described.
Dated this 13th day of November 1894.
For the Applicants,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.