IMPROVED PROCESSES OF OBTAINING BAS RELIEFS, MEDALS, CASTS, DIES, MATRICES, AND THE LIKE BY PHOTOGRAPHY, AND MEANS OR APPARATUS TO BE EMPLOYED IN SUCH PROCESSES
Year: 1881

page_text: LETTERS PATENT to Ernest de Pass, of the Office for British & Foreign
Patents, 68, Fleet Street, in the City of London, Patent Agent, for an
Invention of "IMPROVED PROCESSES OF OBTAINING BAS RELIEFS, MEDALS,
CASTS, DIES, MATRICES, AND THE LIKE BY PHOTOGRAPHY, AND MEANS OR
APPARATUS TO BE EMPLOYED IN SUCH PROCESSES." A communication from
abroad by William Henry Guillebaud, of 17, Boulevard Saint-Martin, Paris,
Franca
PROVISIONAL SPECIFICATION left by the said Ernest de Pass at the Office
of the Commissioners of Patents on the 10th October 1881.
ERNEST DE PASS, of the Office for British & Foreign Patents, 68, Fleet Street, in
the City of London, Patent Agent. "IMPROVED PROCESSES OF OBTAINING BAS
RELIEFS, MEDALS, ČASTS, DIES, MATRICES, AND THE LIKE BY PHOTOGRAPHY,
AND MEANS OR APPARATUS TO BE EMPLOYED IN SUCH PROCESSES." A commu-
nication from abroad by William Henry Guillebaud, of 17, Boulevard Saint-Martin,
Paris, France.
This Invention has for its object improved processes and means for obtaining by
photography, bas reliefs, medals, casts, dies, matrices, and the like, the outlines of
which may be in relief or rounded, and which may be made of any metal or suitable
material. According to the said Invention such objects are produced by means of
the actinic action of diffused light passing through a plate of ground or translucent
glass, on which is reproduced or transferred the photograph of the object or picture
to be reproduced in relief, and falling on sensitized gelatine, whether in a solid or
liquid state.
The Invention is based on the discovery of employing diffused light, and placing
the photograph at a certain distance from the sensitized surface of the gelatine or
other analogous substance, such as albumen, substances of one of which the mould
is to be made.
When the substance is exposed to the light, the outlines and details of the mould
become rounded or bevelled to a greater or less degree, according to the distance
between the photograph and the sensitized material.
To obtain the diffusion of the light in a convenient manner I dispense with the

page_text: use of transparent glass ordinarily employed for taking the negative or the positive,
and instead thereof I use ground glass, which is only translucent and more or less
opaque according to the result to be obtained.
By these means the glass acquires the property of diffusing the light, and if a
stronger diffusion be required the glass may be ground on both sides, and very
good results can be obtained by using a milky white glass, when it must be exposed
to avery strong light or to the sun light.
The diffusion of the light will be increased in proportion as the diffusing surface
is brought nearer to the photograph.
The negative or the positive, after being reproduced on or transferred to the
ground glass, is covered as usual with a thin layer of varnish, which leaves the
face of the photograph visible.
After this operation the sensitized gelatine or other analogous substance employed
is placed at a suitable distance from the photograph in a manner hereinafter set
forth, but as the diffused light if at too great a distance would produce a blurred
or indistinct picture or image, a certain amount of practice is necessary to judge at
what distance from the face of the photograph the gelatine or other material
employed should be placed in order to produce a distinct picture with the necessary
relief of the outlines. If the light be well diffused, about 1/ would be the
distance at which the gelatine or other material should be placed from the face of
the photograph in order to produce a good proof showing all details.
m
With a very much diffused light the face of the photograph is separated from
the gelatine or the like by applying to the photograph one or more coats of thick
copal varnish or clear. white shellac. If a greater distance be necessary, I interpose
between the photograph and the gelatine or the like a more or less thick layer of
insoluble gelatine or of collodion; or if the distance be still greater, I employ a sheet
of clear mica or a sheet of glass of the necessary thickness.
After the gelatine sheet or the like has been fixed at a suitable distance from the
photograph, the whole is exposed to the light in the usual manner, the light being
thrown on to the gelatine through the ground glass and the photograph which is
fixed thereon; the gelatine sheet is then subjected to the action of water in any of
the methods known as the "gelatine process."
By these means a mould having rounded outlines is produced, and with this
mould I obtain, by well known processes, casts or counter-moulds in plaster of
Paris, wax, or other suitable material, and by electrotyping or stereotyping, I
obtain from this cast a mould, a die, or a metallic plate, which can be used for
stamping, moulding, pressing, &c.
The application of this process may also be effected in an advantageous manner
by employing the gelatine in a liquid state, or even in the condition of a jelly; the
gelatine not being in direct contact with the photograph can be instantly removed
after exposure to the light without destroying the photograph, so that if the
operation be not satisfactory another photograph can be obtained immediately.
For carrying this part of the Invention into effect, the sensitized material is
exposed to the light when poured (whilst in a liquid state) into a flat trough, one
of the sides of which is constituted by the photograph. The apparatus employed for
this purpose consists of a frame open at top and capable of receiving the photograph,
of a bottom plate, and an elastic packing (by means of which the trough can be
varied in width) interposed between the edges of the photograph and the bottom
plate, and of a locking device arranged to act against the bottom plate; the whole
forming a shallow trough of variable capacity. The photograph rests against
shoulder pieces formed on the frame, a supplementary plate of glass being usually
placed in front of the photograph, and a sheet of mica or other transparent material
at back to protect it.
A material, such as gelatine or albumen, is rendered sensitive to the actinic rays
of light by the addition of water and bichromate of potash or other matters in
suitable proportions, and the said material or solution in its liquid state (that is to
say, when it is sufficiently hot to remain liquid) is poured into the trough so as to

page_text: form a layer or coating of about 6m/m in thickness (more or less), and the material
thus enclosed is immediately exposed to the rays of light passing through the
photograph. Care must however be taken to keep the whole at a temperature of
about 29° cent. (85° F.) to avoid solidification of the material by cooling.
The frame is then placed in a position which allows the rays of light to fall
perpendicularly on the photograph.
By the light passing through the transparent or translucent photograph and
falling on the sensitized material, this wherever the light strikes it solidifies in
proportion to the intensity of the light, and it is caused to adhere solidly to the
transparent material placed behind the photograph, or to the photograph itself,
leaving the other part or the remainder of the material (which is not affected by
the light) in the liquid state. When the material has been exposed a sufficient
time the frame is taken into a dark room, and the liquid portion of the material
emptied from the trough into a suitable receiver so that it can be used again; the
frame is then opened, and the solidified portion of the material is freed from the
liquid portion which still adheres thereto, this solidified portion forming a mould
which exactly represents in the different gradations of depth the different gradations
or tints of light and shade of the photograph; this mould is then treated in
the same manner as are the moulds obtained by the well known “gelatine
process."
When the gelatine has been separated from the photograph by a coating or
layer of copal varnish or shellac covering the photograph, it can be removed by
simply passing a thin steel blade between the gelatine and the layer or coating of
varnish without deteriorating the photograph, and a number of moulds can be
obtained with the same photograph.
If the transparent material which is placed at the back of the photograph is a
sheet of glass or of mica, it should be albumenized before being used in order to
cause the matrix to adhere thereto. This transparent sheet may however be made
of ground glass, or of insoluble gelatine, of varnish, or of collodion.
The special advantages afforded by the use of the material in a liquid state are
cheapness, any part of the solution or material not actually forming part of the
monid being saved to serve again; great saving of time in preparing and manipu-
lating the plates, and the solution before exposing them, and furthermore, the
possibility of exposing the suitably employed liquid perpendicularly to the direct
rays of the light or of the sun.
The frame berein described is capable of various modifications, the essential
feature thereof being that it constitutes a trough or shallow vessel, one side of
which is formed by the photograph.
In manufacturing moulds, dies, or materials in relief by means of one of the
processes above described, the following is the method employed, it being under-
stood that the means may be varied in details.
I first take a negative or a positive, according to the results desired, of the
object or of the design which is to be represented on the mould, die, or matrix; if
this mould is to be used for stamping or for relief printing I take the negative on
a sheet of ground glass in order to obtain rounded outlines, which, especially for a
deep mould, are alone suitable for this work; or instead of the negative any other
transparent or translucent photograph may be employed.
By means of the actinic action of the light passing through the negative or the
photograph on a layer of sensitized gelatine or other suitable material, such as
albumen, I obtain a preliminary mould, and from this mould I obtain another
mould in plaster, and from this latter I make a mould of about 11% in thickness,
in wax or other materials capable of fulfilling the same purpose as the wax.
Before forming the preliminary mould it is necessary that the photograph should
be touched up, that is to say, all the dark parts in the subject which, from their
natural position, would be in relief so touched as to appear white, and all the light
parts in the subject which would be sunk retouched in order to appear dark, or
vice verad

page_text: The wax cast obtained from the plaster mould is much smaller than this latter,
because the wax, or its equivalent, shrinks on cooling 3 or more for a subject
of 12 centimeters in length; therefore when a cast of an exact is required it
is necessary to ascertain exactly the shrinking of the wax or its equivalent on a
surface of the size the mould is to have, and to take the negative proportionally
large, the plaster mould becoming consequently equally large in proportion.
I then transfer to a tablet or plate of wood or other material of about 5"/m. in
thickness an impression or print of the outline of the photograph or subject of the
exact size of the cast by means of tracing paper, for instance; I then cut out the
outline of the picture on the tablet (say with a very fine toothed saw), taking care
that the saw-cut is within the outline, and I thus obtain a rigid framing corre
sponding to the edges of the cast. I now heat the framing plate in any suitable
manner, and I place the cast thereon face upwards so that the edges thereof are
parallel or nearly so with the edges of the framing; I then press the edges of the
cast, and when the framing plate becomes cool the cast adheres firmly thereto; I
thus obtain a cast of the exact size of the picture surrounded by the rigid framing,
but free or exposed on the face as well as on the back.
The whole is then fixed on a support or table suitably constructed for the
purpose of leaving the front and back of the mould uncovered, and the cast is
modeled in the required manner.
It will be seen that by this arrangement of the cast the artist has now the free
use of his hands to model by pressure either the front or the back as necessary, to
round, chase, or curve the same upwards or downwards. He has before him the
picture or the portrait from which he is working, and he can in a very short time
model it to perfection. The edges of the cast are rigidly held in place by the
framing plate which adheres thereto, so that the pressure from above and below
for rounding the figure does not affect them in any way, and does not alter the
exact size of the cast, which is very important for stamping in relief or in alto-
relievo and other work of the same kind.
The back of the cast which now has taken a hollow form can be filled up to the
level of the front of the framing with plaster of Paris or other suitable material to
consolidate the cast, the object being reversed for this purpose, so that when this
filling bas hardened the mould can be handled without losing any of its relief,
roundness, or outline.
The mould can then be electrotyped or stereotyped by known means, thus
producing a mould, a die, or a matrix in copper or other metal which can be used
for stamping the relief or other like kind of work; or else the mould can be used as
a model for moulding in sand, ornaments of copper, silver, bronze, or other metal
which can then be finished by chasing in the usual manner.
I now proceed to describe means and processes to be employed for obtaining
photographs in alto relievo, although they are capable of slight modifications in
details.
The suitable manufacture of a mould or of a die for producing a photographic
portrait in relief is an exceedingly delicate operation, although it can be performed
rapidly and at little expanse.
The proofs can be mounted on cardboard; they may then be allowed to dry before
being reproduced in relief; or they can be placed on the mould unmounted, and the
cardboard coated with gum or paste just before submitting them to the action of
the stamp or die producing, the relief. Both ways give good results if executed
with care.
According to my process, I take a negative (or a positive, according to the process
which may be further employed), and I touch it up so that the dark portions of
the portrait which are to be in relief in the mould are reproduced as if they had
been white instead of being black, and all the light portions of the portrait, which
must be sunk in the mould, are touched up so as to be black, or vice versa (for
instance, black hair in the negative must be made to appear as if it had been white
in the portrait); if the back ground is not required it is removed by scraping.

page_text: The negative (or the positive) is taken on a ground glass, either on the ground
face or on the smooth face, if the glass be ground on one side only, but I prefer
that the glass should be ground on both sides. A gelatine mould of the picture
made on smooth transparent glass, obtained by an actinic action, has square
rectangular ridges throughout, so that for the setting in relief the square ridges cut
the paper or other material whereon the relief is to be made, and for this reason
moulds of this kind cannot be successfully used for the production of reliefs.
By employing a ground and translucent glass the light is diffused and the out-
lines of the gelatine mould become bevelled; but for obtaining rounded outlines the
front of the portrait must be placed at a slight distance from the sensitized material,
such as gelatine or albumen, which must serve for making the mould during the
exposure, as has been herein before stated.
The distance between the portrait and the gelatine at the same time as the
diffusion produced by the ground glass, allows the diffused light to penetrate, as it
were, under the outlines of the figure, and a mould with bevelled and rounded
edges and details of great beauty to be obtained; and when this mould is used to
produce the relief a portrait is obtained which is neither cut, cracked, or torn, and
more pleasing to the eye than if it had sharp broken outlines, even if the latter
could be produced without tearing the paper.
From the mould obtained by the actinic action of the more or less thick coating
or layer of sensitized gelatine I take in the usual manner a plaster mould represent-
ing the sunk or impressed figure; from this plaster mould I take by well known
means a cast in wax, gutta percha, vegetable wax, shoemakers' wax, or other
equivalent material, which when the figure in the plaster mould is sunk or impressed,
represents the figure in relief. This wax cast should generally be about 3/m in
thickness, more or less.
As it has been already stated, the negative (or the positive) must be taken larger
than the actual size of the portrait to be produced in relief, and to determine the
exact proportion I place a wax mould on a plaster of Paris tablet, provided with a
graduated scale of about 30 centimetres in length.
When the cooling is effected I remove the wax mould representing the graduated
scale. This wax mould is however shorter than the plaster mould, by reason of
the contraction of the wax when cooled, and it serves to determine the size of the
required negative (or of the positive.)
The plaster mould from which the wax cast is obtained as above stated being of
the same size as the negative (or the positive) which has served to make the mould,
it is no longer required, but the wax form will represent the figure in relief, and of
the exact size necessary to produce the relief of the proof, all the details being in
suitable relief, and not according to the lights and shades, or the colours, but
according to the natural position and form, only the whole figure is flat as the
natural curve of the figure, and the details are not reproduced.
The wax mould having been obtained by the process just above described, and
having been modeled by the artist, in the manner described, the surface of this
mould is covered with black lead and is subjected to an electrotyping process BO as
to obtain a concave electro type whose convex face is carefully lined with a metal
backing, and from which a matrix can be taken in any metal or in any suitable
material by known means.
The proofs are then placed between the concave electrotype and the matrix, and
the relief is produced by pressure.
Great care must be taken to make the electrotype and the matrix of a uniform
thickness, and to place the proofs on the electrotype in such way as to register
them properly, which can be done by any of the numerous registering processes
known, so that the figure of the proof corresponds with the portions of the mould

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Ernest de Pass in the Great Seal Patent Office on the 5th April
1882.
ERNEST DE PASS, of the Office for British & Foreign Patents, 68, Fleet Street, in
the City of London, Patent Agent. "IMPROVED PROCESSES OF OBTAINING BAS-
BELIEFS, MEDALS, CASTS, DIES, MATRICES, AND THE LIKE BY PHOTOGRAPHY, AND
MEANS OR APPARATUS TO BE EMPLOYED IN SUCH PROCESSES." A communication
from abroad by William Henry Guillebaud, of 17, Boulevard Saint-Martin, Paris,
France.
This Invention has for its object improved processes and means for obtaining by
photography bas-reliefs, medals, casts, dies, matrices, and the like, the outlines
of which may be in relief or rounded, and which may be made of any metal or
suitable material. According to the said Invention such objects are produced by
means of the actinic action of diffused light passing through a ground or translucent
plate of glass, on which is reproduced or transferred the photograph of the object
or picture to be reproduced in relief and falling on sensitized gelatine whether in a
solid or liquid state.
The Invention is based on the discovery that by using diffused light and placing
the picture or photograph at a certain distance from the surface of the sensitized
gelatine or other analogous substance, such as albumen, from which the mould is to
be produced while exposed to the light, the edges and details of the mould become
rounded, bevelled, or slanting to a greater or less degree, according to the distance
of the picture or photograph from the sensitized medium.
To properly diffuse the light I dispense with the use of transparent glass
ordinarily employed for taking the negative or the positive, and instead thereof I
use ground glass, which is only translucent and more or less opaque according to
the result desired.
By these means the glass acquires the property of diffusing the light, and if a
stronger diffusion be required the glass may be ground on both sides, and very good
results can be obtained by using milky white glass, when it must be exposed to a
very strong light or to the sun. The diffusion of the light will be the greater the
nearer the diffusing surface is brought to the photograph.
The negative or the positive, after being produced upon or transferred to the
ground glass, is covered as usual with a thin coat of varnish which leaves the face
of the photograph visible.
After this operation the sensitized gelatine or other analogous substance employed
is placed at a suitable distance from the photograph in a manner hereinafter set
forth, but as the diffused light will at too great a distance produce a blurred or
indistinct picture or image a certain amount of practice is necessary to judge at
what distance from the face of the photograph the gelatine or other material
employed should be placed in order to produce a distinct picture with the necessary
relief of the outlines. If the light be well diffused about (1 milimeter) of an
inch would be the limit at which the gelatine or other medium must be placed
from the face of the photograph in order to produce a good proof showing all
details.
For very diffused light the face of the photograph is separated from the gelatine
or the like by applying to the photograph one or more coats of thick copal varnish
or clear white shellac. If a greater distance be necessary, I interpose between the
photograph and the gelatine or the like a sheet of insoluble gelatine or of collodion
of more or less thickness, or if the distance is to be still greater a sheet of clear
mica or a sheet of glass of the necessary thickness is employed,

page_text: After the sheet of gelatine or the like has been adjusted at a suitable distance
from the photograph the whole is exposed to the light in the usual manner, the
light being thrown on to the gelatine through the ground glass and the photograph
fixed thereon upon the gelatine, then the sheet of gelatine is subjected to the action
of water in any of the methods known as the gelatine process.
By these means a mould is obtained with rounded outlines or edges, and from
this mould I obtain by well known processes casts or counter moulds in plaster of
Paris, wax, or other suitable material, and by electro-typing or stereotyping I obtain
from this cast a metallic mould, a die, or a plate, which can be used for embossing,
stamping, moulding, pressing, &c.
The application of this process may be also effected in an advantageous manner
by employing the gelatine in a liquid state or even in the condition of a jelly; the
gelatine not being in direct contact with the photograph can be readily removed after
exposure to the light without destroying the photograph, so that if the operation
be not satisfactory another photograph can be obtained immediately.
For carrying this part of the Invention into effect the sensitized material is
exposed to the light when poured (whilst in a liquid state) into a cell or flat trough
one side of which is formed by the photograph. The apparatus employed for this
purpose consists of a frame open at top and capable of receiving the photograph of
a back plate and of an electric packing or cushion interposed between the edges of the
of photograph and the back plate and a locking device, arranged so as to act on the
back plate, the whole forming a shallow call or trough of variable capacity as
hereinafter fully described.
In the accompanying Drawings, Figure 1 is an elevation in perspective, and
Fig. 2 a vertical section of the apparatus employed for carrying into effect the
application of the gelatine in a liquid state for the purpose proposed.
A is the frame containing the photograph B; O is the back plate; D, the
packing or cushion; and E, the locking or clamping device.
One side of the frame A is left open, and the and the photograph B bears against
the shoulders F formed on the closed sides of the frame, a supplementary plate G of
ground glass being usually placed in front of the photograph, and a sheet of mica
or other transparency behind for its protection. The back plate C is fitted into
the frame A, and the packing D is interposed between it and the photograph B
at the edges thereof, thus creating a space trough or cell h, one side of which is
formed by the photograph.
The packing or cushion D consists of a piece of india-rubber tubing, which
being compressible and expansible allows the trough or call to be varied in
width
The locking or clamping piece E consists of a bar extending across the back
plate C, and which is connected to the opposite sides of the frame A by sarows i,
so that by serewing them up the bar can be pressed against the back płata.
A material such as gelatine or albumen is rendered sensitive to the actinic rays
of light by the addition of water and bichromate of potash, or other materials in
suitable proportions, and the said material or solution in its liquid state (that is to
say, when it is sufficiently hot to remain liquid) is poured into the call or trough
Bo as to form a layer or coating of about of an inch (6 milimeters) in thickness
(more or less), and the material thus enclosed is immediately exposed to the rays
of light passing through the photograph, care being taken however to keep the
whole at a temperature of about 85° F. (29° cent) to avoid the hardening of the
medium by cooling.
The frame is then placed in a suitable position, which allows the the rays of
the light to fall perpendicularly on the photograph.
By the action of light passing through the transparent or translucent photo-
graph and falling upon the sensitized medium, this latter is solidifted wherever
the light strikes it in proportion to the intensity of the light, and it is caused to
adhere firmly to the transparent material placed behind the photograph or to the
photograph itself, leaving the other or remaining portion of the medium in its

page_text: liquid state. When the medium has been exposed a sufficient time, the frame is
taken into a dark room and the liquid portion of the medium emptied from the
trough h into a suitable receiver so that it can be used again; the frame is then
opened, and the solidified or hardened portion of the medium or material is freed
from the liquid portion which still adheres thereto, this solidified portion forming
a mould which represents exactly in the various graduations of depth the different
graduations or tints of light and shade in the photograph. This mould is then
treated in the same manner as are the moulds obtained by the well known
"gelatine process."
When the gelatine has been separated from the photograph by a film, coating, or
layer of copal varnish or shellac covering the photograph, it can be removed by
simply passing a thin flat steel blade between it an the layer or coating of varnish
without injuring the photograph, and a number of moulds can be obtained with
the same photograph.
If the transparent material which is placed behind the photograph be a sheet of glass
or of mica, it should be albumenized before being used in order to cause the medium to
adhere thereto. This transparent sheet may however be made of ground glass, or
of insoluble gelatine, of varnish, or of collodion. The special advantages offered by
the use of the material in a liquid state are cheapness, any portion of the solution
or material not actually forming part of the mould being saved to serve again,
great saving of time in preparing and manipulating the plates and the solution
before exposing them, and and further-more the possibility of exposing any suitable
liquid medium perpendicularly to the direct rays of the light or of the sun.
The frame herein described is capable of various modifications, the essential
feature thereof being that is constitutes a cell, or trough, or shallow vessel, one side
of which is formed by the photograph.
In manufacturing moulds, dies, or matrices in relief by means of one of the
processes above described the following is the method employed, it being understood
that the means may be varied in details:-
I first take a negative or a positive according to the results desired of the object
or of the design which is to be represented on the mould, die, or matrix. If this
mould is to be used for stamping or embossing I take the negative on a plate of
ground glass in order to obtain rounded outlines or edges, which especially in a
deep mould are the only proper edges for such work, or instead of the negative any
other transparent or translucent picture or photograph may be employed. By
means of the actinic of the light passing through the negative or the photo-
graph upon a sensitized layer of gelatine or other suitable material, such as
albumen, and in any known manner, I obtain a preliminary mould, and from this
mould I obtain also in a known manner another mould in plaster, and from this
latter I make a mould of about 1 of an inch (11/) in thickness in wax or other
materials capable of fulfilling the same purpose as the wax.
Before taking the preliminary mould it is necessary that the photograph should
be retouched, that is to say, all the dark parts of the subject which from their
natural position should be in relief, so as to appear white, and all the light parts
in the subject which would be sunk are retouched so as to appear dark, or vice
Ver80.
4
The wax cast obtained from the plaster cast or mould is much smaller than this
latter, because the wax or its equivalent shrinks in cooling as much as of an
inch (3) or more on a subject of 4 inches (12 centimeters) in length. Therefore
when a cast of exact size is required it is necessary to ascertain exactly the
shrinkage of the wax or its equivalent on a surface the size of the cast or mould,
and to take the negative correspondingly larger, the plaster cast or mould becoming
consequently proportionally larger. I now transfer on to a tablet or plate of wood
or other material of about of an inch (5"/m) in thickness, an impression or print
of the outline of the photograph or subject of the exact size of the cast, as, for
instance, by means of tracing paper. I then cut out the outline of the picture on
the tablet (say, with a very fine toothed saw) taking care that the saw-cut is.

page_text: within the outline, and I thus obtain a rigid framing corresponding to the edges of
the cast. I now heat the framing plate in any suitable manner, and place the cast
thereon face upwards so that the edges are parallel or nearly so with the edges of
the framing. I then press down the edges of the cast, and when the framing plate
becomes cool the cast adheres firmly thereto; I thus obtain a cast of the exact size
of the picture surrounded with a rigid framing, but left open or exposed on the
face as well as on the back.
The whole is then fixed on a support or table suitably constructed for the
purpose, leaving the front and back of the cast exposed, and the cast is modelled in
the desired manner.
It will be seen that by this arrangement of the cast the artist has now the free
use of both his hands to model by pressure from the front or back, as may be
required, to round up, chase, or curve the same upwards or downwards. He has
before him the subject from which he works, and he can in a very short time
model it to perfection.
The edges of the cast are rigidly held in place by the framing plate which
adheres thereto, so that the pressure from above or below for rounding up the
figure does not affect them in any way, and does not alter the exact size of the
cast, which is very important for embossing or for alto relievo and other work of
the same kind.
The back of the cast, which has now assumed a hollow form, can then be filled
up to the level of the front of the framing with plaster of Paris or other suitable
material to solidify the cast, the object being inverted for this purpose, so that
when this filling has set or become hardened the cast can be handled without
losing any of its relief, roundness, or outline.
The mould can then be electrotyped or stereotyped by known means, thus
producing a mould, a die, or a matrice in copper or other metal, which can be used
for embossing, stamping, or other like kind of work, or else the cast can be used as
a pattern for moulding in sand ornaments of copper, silver, bronze, or other metal,
which may afterwards be finished by chasing as usual.
I now proceed to describe means and processes I employ for obtaining photo-
graphs in alto relievo, although they are capable of slight modifications in
details.
The suitable manufacture of a mould or of a die for producing a photographic
portrait in relief is an exceedingly delicate operation, although it can be performed
rapidly and at little expense.
The proofs can be mounted on cardboard; they may then be allowed to dry
before being produced in relief, or they can be placed on the mould unmounted
and the cardboard coated with gum or paste just before submitting them to the
action of the stamp or die producing the relief. Both ways give good results if
executed with care.
According to my process I take a negative (or a positive, according to the
process which may be further employed) and I retouch it, so that the dark
portions of the portrait which are to be in relief in the mould are reproduced
as if they had been white instead of being black, and all the light portions of the
portrait, which must be sunk in the mould, are retouched, so as to be black, or vice
versa (for instance, black hair in the negative must be retouched so as to appear as
if it had been white in the portrait); if the background is not required it is
removed by scraping.
The negative (or the positive) is taken on a ground glass, either on the ground.
face or on the smooth face if the glass be ground on one side only, but I prefer
that the glass should be ground on both sides. A gelatine mould of the picture
made on smooth transparent glass obtained by an actinic action has square
rectangular ridges throughout, so that for the setting in relief the square
ridges cut the paper or other material on which the relief is to be made, and for
this reason moulds of this kind cannot be successfully used for the production of
reliefs.

page_text: By employing a ground and translucent glass the light is diffused and the
outlines of the gelatine mould become bevelled, but for obtaining rounded edges or
outlines the front of the portrait must be placed at a slight distance from the
sensitized material (such as gelatine or albumen), which must serve for making the
mould during the exposure, as has been hereinbefore stated. The distance between
the portrait and the gelatine at the same time as the diffusion produced by the
ground glass allows the diffused light to penetrate, as it were, under the outlines
of the figure, and a mould with bevelled and rounded edges and details of great
beauty to be obtained, and when this mould is used to produce the relief a portrait
is obtained which is neither cut, cracked, nor torn, and more pleasing to the eye
than if it had sharp broken outlines, or even if the latter could be produced without
tearing the paper.
From the mould obtained by the actinic action on the more or less thick coating
or layer of sensitized gelatine I take in the usual manner a plaster mould
representing the sunk or impressed figure; from this plaster mould I take by
known means & cast in wax, gutta percha, vegetable wax, pitch, or other equivalent
material, which (when the figure in the plaster mould is sunk or impressed)
represents the figure in relief. This wax cast should generally be about of an
inch (3) in thickness more or less.
As it has been already stated, the negative (or the positive) must be taken
larger than the actual size of the portrait to be produced in relief, and to
determine the exact proportion I place a wax mould on a plaster of Paris
tablet provided with a graduated scale of about 11 inches (30) in length.
When the cooling is effected I remove the wax mould representing the graduated
scale. This wax mould is, however, smaller than the plaster mould by reason of
the contraction of the wax when cool, and it serves to determine the size of the
required negative (or of the positive).
The plaster mould from which the wax cast is obtained, as above stated, being
of the same size as the negative (or the positive), which has served to make the
mould it is no longer required, but the wax form will represent the figure in
relief and of the exact size necessary to produce the relief of the proof, all the
details being in suitable relief, and not according to the lights and shades or
the colours, but according to the natural position and form, only the whole
figure is flat, as the natural curve of the figure and the details are not
reproduced.
The wax mould having been obtained by the process just above described, and
having been modelled by the artist in the manner described, the surface of this
mould is covered with black lead and is subjected to an electrotyping process, 80
as to obtain a concave electrotype whose convex face is carefully lined with a metal
backing and from which a matrix can be taken in any metal or in any suitable
material by known means.
The proofs are then placed between the concave electrotype and the matrix, and
the relief is produced by pressure.
Great care must be taken to make the electrotype and the matrix of a
uniform thickness and to place the proofs on the electrotype in such way as to
register them properly, which can be done by any of the numerous registering
processes known, so that the figure of the proof corresponds with portions of the
mould.
Having now described the nature of the said Invention, and in what manner the
same may be performed, I declare that I claim,—
1. The within described process of producing photomoulds, which consists in
transferring the photograph or picture to a sheet of ground or translucent glass,
then applying thereto a sheet or layer of sensitized gelatine or analogous substance,
then exposing the gelatine to diffused light through the ground or translucent
glass, and then exposing the gelatine to the action of water, substantially as set
forth.
2. The within described process of producing photo-moulds, which consists in

page_text: transferring the photograph or picture to a sheet of ground or translucent glass,
then adjusting a sheet or layer of sensitized gelatine or analogous substance
at a suitable distance from the picture, then exposing the whole to the action of
light, and finally treating the sheet or layer of gelatine with water, substantially as
set forth.
3. The within described process of producing photographs in relief, consisting
in exposing in a liquid state a sensitized medium to the actinic action of light
through a positive, or a negative, or other transparent or translucent picture, by
pouring such medium in a liquid state into a trough, cell, or other receptacle, one
side of which is formed by the picture or photograph to be reproduced.
4. The combination, substantially as hereinbefore set forth, of the frame open on
one side and adapted to receive the transparent or translucent photograph or
picture, the back plate, the packing or cushion interposed between the photograph
or picture, and the back plate at the edges thereof, forming a variable trough or
cell, and the locking or clamping device, arranged to act on the back plate.
5. The within described process of making moulds, dies, matrices in relief or in
alto relievo, which consists in first obtaining a mould by the actinic action of light
upon a sensitized medium through a negative or a positive or a transparent or
translucent photograph or picture, then obtaining a plastic cast from such mould,
applying this plastic cast to a border frame or backing, and then modelling the
same in the desired manner, as set forth.
6. The within described process of producing a photographic portrait repre-
senting the main figure in alto-relievo by first making by actinic action a
mould (in gelatine or other analogous substance), with rounded, bevelled, or
alanting edges, then producing with this mould a plastic cast, then rounding said
cast so as to correspond with the natural object, and then obtaining with this
rounded plastic cast a concave electrotype and another matrix, and lastly by
transforming in alto relievo the photographie impression by the combined action of
the electrotype and matrix, substantially as set forth.
7. The employment of the means herein set forth, forming a framing allowing
the artist to work on the photographically obtained wax mould and to use both
hands in modelling in order to obtain the desired effects of relief.
8. The special arrangements herein described, or any mere modification of the
details and accessory arrangements thereof.
In witness whereof, I, the said Ernest de Pass, have hereunto set my
hand and seal, this Third day of April, in the year 1882.
ERNEST DE PASQ
al