A NEW AND IMPROVED PROCESS FOR. OBTAINING COLORED PHOTOGRAPHIC PICTURES
Year: 1878

page_text: LETTERS PATENT to Jean Baptiste Germeuil-Bonnaud, of Paris (France),
Photographer, for the Invention of "A NEW AND IMPROVED PROCESS FOR.
OBTAINING COLORED PHOTOGRAPHIC PICTURES."
PROVISIONAL SPECIFICATION left by the said Jean Baptiste Germeuil-
Bonnaud at the Office of the Commissioners of Patents on the 11th October
1878.
"C
A
33.
JEAN BAPTISTE GERMEUIL-BONNAUD, of Paris (France), Photographer.
NEW AND IMPROVED PROCESS FOR OBTAINING COLORED PHOTOGRAPHIC PICTURES."
My Invention consists in a process for obtaining coloured photographic pictures.
by means of two successive impressions from the negative, the first being a weak
impression to give the outline for guiding the application of the colouring, and the
second, after the colours have been applied, boing an impression of sufficient
strength to give the clear drawing and shading. In carrying out this process I first
render the paper sensitive by soaking it for about two minutes in a bath consisting
of 3 parts nitrate of silver at 6%, and 3 parts glycerine to 50 parts distilled water,
and then drying it. I take on this a weak impression from the negative, just
enough to give the outlines, develop, and dry it; I then apply the colours flatly
without regard to shading or softening off, but taking care to have the tints brighter
than they are intended to be finally, and to apply them lightly. They may be
applied with water alone, but it is better with a mixture of 1 part gum Arabic and
1 part glycerine to 100 parts distilled water. The parts to be coloured should be
first moistened to make them take the colour evenly, and then the colours are
applied by a hair pencil moistened with the mixture above mentioned. Almost
any colours may be used, except such as contain white or vermillion in their compo-
sition. For the flesh tints red ochre with yellow ochre, or silver yellow toned with
lake may be employed. After the proof is coloured and dried it is albuminised in
a bath prepared as follows:-Whites of egg mixed with about 15 grains of sal
ammoniac to each egg are beaten up till they are just about to turn to a snowy
CD..

page_text: appearance; they are then allowed to remain still for several hours and filtered
through linen. The coloured proof is left a few seconds in this bath, any bubbles
being removed by a hair pencil, and is then dried, after which it is again rendered
sensitive in a bath consisting of 4 parts nitrate of silver at 8%, and 3 parts
glycerine to 50 parts distilled water. The proof is then again subjected to the 5
action of light through the negative, the impression being continued until the half
tints are quite brought out. It is then developed and fixed in the usual way, care
being taken that the developing bath should give a ruddy tint, so that the flesh
colours may be full and clear.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Jean Baptiste Germeuil-Bonnaud in the Great Seal Patent Office on
the 20th March 1879.
"A
JEAN BAPTISTE GERMEUIL-BONNAUD, of Paris (France), Photographer.
NEW AND IMPROVED PROCESS FOR OBTAINING COLOURED PHOTOGRAPHIC PICTURES."
My Invention consists in a process for obtaining coloured photographic pictures
by means of two successive impressions from the negative, the first being a weak
impression to give the outline for guiding the application of the colouring, and the
second, after the colours have been applied, being an impression of sufficient
strength to give the clear drawing and shading. In carrying out this process I first
render the paper sensitive by soaking it for about two minutes in a bath consisting
of 3 parts nitrate of silver at 6%, and 3 parts glycerine to 50 parts distilled water,
and then drying it. I take on this a weak impression from the negative, just
enough to give the outlines, develop, and dry it. I then apply the colours flatly
without regard to shading or softening off, but taking care to have the tints brighter
than they are intended to be finally, and to apply them lightly. They may be
applied with water alone, but it is better with a mixture of 1 part gum Arabic and
1-part glycerine to 100 parts distilled water. The parts to be coloured should bo
first moistened to make them take the colour evenly, and then the colours are
applied by a hair pencil moistened with the mixture above mentioned. Almost
any colours may be used, except such as contain white or vermillion in their compo-
sition. For the flesh tints red ochre with yellow ochre, or silver yellow toned with
lake, may be employed. After the proof is coloured and dried it is albuminised in
a bath prepared as follows:-Whites of egg mixed with about 15 grains of sal
ammoniac to each egg are beaten up till they are just about to turn to a snowy
appearance; they are then allowed to remain still for several hours and filtered
through linen. The coloured proof is left a few seconds in this bath, any bubbles
being removed by a hair pencil, and is then dried, after which it is again rendered
sensitive in a bath consisting of 4 parts nitrate of silver at 8%, and 3 parts
glycerine to 50 parts distilled water. The proof is then again subjected to the
action of light through the negative, the impression being continued until the half
tints are quite brought out. It is then developed and fixed in the usual way, care

page_text: being taken that the developing bath should give a ruddy tint, so that the flesh
colours may he full and clear.
When it is desired to produce a number of coloured copies of a subject, such as a
landscape, the first light photographic impression may be dispensed with, the
outlines for guiding the colouring being obtained by lithography, and for the sake
of rapidity and economy both outline and colouring may in such cases be produced
by chromo-lithography, after which the impression is rendered sensitive and photo-
graphed from the negative as above described.
Having thus described the nature of the said Invention, and in what manner the
same is to be performed, I claim,―
First. The process for producing coloured photographs, substantially as herein set
forth, that is to say, laying the colours on a faint photographic impression sufficient
to give guiding outlines, albuminising and rendering sensitive the impression after
colouring, and finally taking thereon a second and stronger photographic impression
sufficient to bring out the shades and half tints.
Second. The latter portion of the process referred to in the preceding claim, that
is to say, albuminising and rendering sensitive a coloured subject and taking thereon
a photographic impression, substantially as herein described.
In witness whereof, I, the said Jean Baptiste Germeuil-Bonnaud, have here-
unto set my hand and seal, this Fourth day of March, in the year of our
Lord One thousand eight hundred and seventy-nine.
ARMENGAUD, jeune,
of Paris,
Bd. de Strasbourg, 23,
Civil Engineer.
Witness.
J. B. GERMEUIL-BONNAUD. (L.S.)