A NEW OR IMPROVED PROCESS AND APPARATUS FOR PRODUCING PHOTOGRAPHIC IMAGES UPON OR ORNAMENTING GLASS, OR GLAZED, OR ENAMELLED ARTICLES
Year: 1876

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for the Invention of "A NEW OR IMPROVED
PROCESS AND APPARATUS FOR PRODUCING PHOTOGRAPHIC IMAGES UPON OR
ORNAMENTING GLASS, OR GLAZED, OR ENAMELLED ARTICLES." A communi-
cation from abroad by Marcel Charbonnier and Robert Charbonnier, both of
Longchamp, near Genlis, in the Republic of France, Potters.
aled the 26th January 1877, and dated the 22nd August 1876.
"
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 22nd August 1876.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "A NEW OR IMPROVED PROCESS AND APPARATUS FOR PRODUCING
PHOTOGRAPHIC IMAGES UPON OR ORNAMENTING GLASS, OR GLAZED, OR ENAMELLED
ARTICLES." A communication from abroad by Marcel Charbonnier and Robert
Charbonnier, both of Longchamp, near Genlis, in the Republic of France, Potters.
This Invention relates chiefly to a process which it is proposed to designate
'photochrosic" for ornamenting enamels, and which is performed by means of
positive photographic impressions upon glass, or of photographs, lithographs,
engravings, and the like upon transparent paper," this system being equally
applicable to enamels to be baked with a sharp fire or in a reverberatory oven, or
by a porcelain fire, and to all ceramic products of flat, oval, or cylindrical form,
among which may be mentioned,-
1st. Earthenware products known as crockery ware covered with a white
opaque glaze upon which decorative or artistic paintings are applied, whether the
said glaze is in a crude condition or otherwise.
2nd. The products in opaque porcelain also known as pipe clay or flint ware
coated with a transparent glaze.
3rd. Products in hard or soft porcelain coated with a transparent glaze.
4th. Glazed or enamelled products in artistic pottery.
5th. Products in glass, crystals, and the like, such for example as glass plates
and glass hollow ware.
6th. Products in biscuit which are to be coated with a transparent glaze.

page_text: As before mentioned the operation is performed by means of positive impressions
which are reproduced exactly by means of light and transferred to the products to
be decorated by means of media portions of which disappear, whilst others are
deposited upon the articles to be decorated in the form of impalpable and vitrifiable
powders which leave in baking pictures not susceptible of change or deterioration,
and the truthfulness of which only depends upon the accuracy of the impression on
the plate.
The operation is carried out in the following manner:-A plate of copper, such
for example as is used for engraving purposes, well smoothed and polished, is taken
and carefully cleaned with a small plug of very fine cotton impregnated with a
mixture of water and impalpable Tripoli powder or rottenstone, after which the
plate is rubbed with a similar plug of cotton, dry and clean.
A solution is prepared containing,-
Bichromate of potash
Honey or sugar
Distilled water
4 parts by weight,
-
10
50
ditto
ditto
The solution is filtered carefully and poured over the copper plate, the operation
being repeated so as to obtain a perfectly uniform coating. As this condition is
essential the plate should be placed upon a small turning board or centrifugal
machine, by the aid of which the uniform distribution of the sensitive layer or
coating is facilitated; it is then dried by means of a small spirit lamp. The plate
thus prepared when cool is then applied with great exactness, and so that contact
shall be complete upon the internal face of the positive plate; it is then to be
exposed to the light which passes through the glass, and in the lights of the picture
destroys the sensitive layer in the proper places.
When it is considered that the plate has been exposed for a sufficient length of
time it is taken off and replaced for a short time over the spirit lamp in order to
prevent it from becoming too sticky, and by means of a very fine brush the
vitrifiable metallic powder in a state of impalpable dust is sprinkled or interspersed
over it. This power which constitutes the coloring enamel is composed of metallic
oxides and of fluxes adapted to the nature of the ceramic products, and the degree of
heat to which they are to be subjected; thus the vitrifiable colors in powder for
quick fire are employed for cominon earthenware and reverberatory colours, or
porcelain colours are employed (also in a state of impalpable powder) for products
baked in a muffle or porcelain kiln.
In laying on the powder with the brush the picture will be seen to develope
itself, and the thickness of the vitrifiable powder may be regulated according to the
qualities of the metallic colours, and taking into consideration the ulterior action
which will necessarily take place during the baking either by removing tones or by
softening the contours. This powdering may be repeated several times if necessary,
the plate being placed at rest and the powder laid on again with the brush until
the tints and half tints are all brought out.
When the picture is completely developed a coat of well filtered collodion com-

page_text: and the whole is carefully lifted off beginning with one side. In this operation the
picture remains adhering to the collodion, and by means of the frame it is deposited
on the enamelled or varnished part which it is desired to ornament, care being
taken that the impalpable powder is not in contact with the said enamel; the
collodion is then carefully cut out round the frame by means of a graver and the
frame removed. The picture when cut out remains thus fixed; it is heated with air
or at a gentle fire, and very fine and well filtered oil of petroleum poured over the
whole. Impurities if any exist may be removed with a brush, and the picture may
be retouched with the same vitrifiable powder nixed with essence of lavender.
The picture fixed and dried in this manner may be placed in an oven in the usual
manner of treating any other description of painting on enamel or glaze, the mode
and amount of baking being moreover adapted to the composition of the vitrifiable
colours employed in a state of impalpable powder.
The positive impressions upon glass before mentioned may be replaced by ordinary
photographs upon transparent paper, the process with this paper being similar to
that adopted with the impression upon glass, with the exception that it requires to
be exposed to the action of light for a longer period, varying in proportion to the
thickness or opacity of the paper. It is also necessary that the pulp of which the
paper is made should be homogeneous, and free from impurities which would
obstruct the luminous rays. The adhesion of the bichromate sensitive coating to
the paper may be prevented by ensuring the dryness of the coat and employing
paper either glazed or covered with a nitrate varnish as for photograplis, also
by placing the paper picture between two plates of very clear glass as thin as
possible.
The plates of glass with the picture are fixed upon the copper plate by means of
say three or four small spring clamps which prevent all slipping of the picture on the
sensitive coat during the operation of exposing it to the action of the light which is
an important condition for obtaining a good result.
The process is carried out in a similar manner when engravings lithographs or
drawings upon paper are employed, such paper being made from pure pulp and
sufficiently thin.
Among the purposes to which this process is applicable may be enumerated the
following:-1st. Reproduction of all artistic works of the great masters, pictures,
drawings, monuments, photographs and the like upon plates, medallions, vases of all
shapes, dishes, plates, and all ceramic products capable of being covered with an
enamel or glaze, whether the said glaze be transparent or opaque, and colored in
such a manner as to form a ground, or whether it is uniformly opaque and of a
plain white color.
In a similar manner pictures may be transferred to biscuits which are to be sub-
sequently covered with a transparent glaze; for this purpose it is necessary to
maintain the biscuits in a wet condition at the moment of performing the operation,
otherwise the collodion will contract and no delay should take place in dipping the
article into the transparent glaze.
The advantage of operating upon products in the condition of biscuit consists in
the possibility of employing bright colors, as the transparent coating which covers
them protects them from the action of the flame. If a delay is inevitable, before
effecting the dipping in the glaze it will be necessary to pour a thin film of petroleum
upon the picture with some siccative, so as to ensure the picture at the time of
dipping being free from grease, which would occasion accidents in the operation.
The baking which fixes the picture renders it by the act of fusion completely
unchangeable, for quick fire colours especially, the reproductions are thus proof
against acids, moisture, and conflagrations.
As the positive plate or proof undergoes no change or deterioration in the
operation it may be reutilized an indefinite number of times, so that the impression
on a single plate may be repeated or reproduced as often as desired.
This process by reason of the fineness of the details which may be obtained is

page_text: likewise applicable to the reproduction of photographs for industrial or business
purposes upon plates not susceptible of change or deterioration, as herein-before
described.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
tho said John Henry Johnson in the Great Seal Patent Office on the
21st February 1877.
"
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "A NEW OR IMPROVED PROCESS AND APPARATUS FOR PRODUCING
PHOTOGRAPHIC IMAGES UPON OR ORNAMENTING GLASS, OR GLAZED, OR ENAMELLED
ARTICLES.' A communication from abroad by Marcel Charbonnier and Robert
Charbonnier, both of Longchamp, near Geulis, in the Republic of France, Potters.
The said Invention relates to a process which it is proposed to designate "photo-
chrosio," for ornamenting enamels, and which is performed by means of positive
photographic impressions upon glass, or of photographs, lithographs, engravings,
and the like, upon transparent paper; this system being equally applicable to
enainels to be baked with a sharp fire, or in a reverberatory oven, or with a porce-
lain fire, and to all ceramic products of flat, oval, cylindrical, or other form. Of the
products, to which the said Invention is applicable, the following may be enumerated,
videlicet,―
First. Earthenware products, known as crockery ware, covered with a white
opaque glaze, upon which decorative or artistic paintings are applied, whether the
said glaze is in a crude condition or baked.
Second. The products in opaque porcelain, also known as pipe clay or flint ware,
coated with a transparent glaze.
Third. Products in hard or soft porcelain, coated with a transparent glaze.
Fourth. Glazed or enamelled products in artistic pottery.
Fifth. Products in glass, crystals, and the like, such for example as glass plates
and glass hollow ware.
Sixth. Products in biscuit, which are to be coated with a transparent glaze.
The operation is performed by means of positive impressions, as before
mentioned, which are reproduced exactly by means of light and subsequently
transferred to the products to be decorated, by means of media portions, which
disappear whilst others are deposited upon the articles to be decorated in the form
of impalpable and vitrifiable powders, which leave in baking pictures not susceptible
of change or deterioration, and the truthfulness of which only depends upon the
accuracy of the impression on the plate.
The operation is carried out in the following manner,-A plate of copper, such,
for example, as is used for engraving purposes, well smoothed and polished, is
taken and carefully cleaned with a small plug of very fine cotton, impregnated with
a mixture of water and impalpable Tripoli powder or rottenstone, after which
the plate is rubbed with a similar plug of cotton, dry and clean.
A solution is prepared, containing,-
Bichromate of potash, about four parts by weight,
Honey or sugar, about
Distilled water, about
ten
fifty
ditto
ditto
This solution is filtered carefully, and poured over the copper plate, the operation
being repeated so as to obtain a perfectly uniform film or coating. Bichromate of
ammonia or other ammoniacal or alkaline bichromates may be substituted for the
bichromate of potash.

page_text: As it is essential that the film or coating should be applied uniformly over the
whole surface the plate is placed upon a small turning board or centrifugal machine,
by the aid of which the uniform distribution of the sensitive film or coating is
facilitated. It is then dried by means of a small spirit lamp. The plate, thus
prepared, when cool, is then applied with great exactness, and so that the contact
shall be complete upon the internal face of the positive plate, it is then exposed
to the light, which passes through the glass. (or paper, when operating with en-
gravings or lithographs), and in the lights of the picture destroys the sensitive film.
or coating in the proper places.
In lieu of employing sunlight artificial light may be employed, such, for example,
as that obtained by means of magneto-electric apparatus, or of apparatus for burn-
ing oxhydric gas, or of any other agent capable of producing a powerful light.
This facility for employing other lights than sunlight, is of considerable advantage
for enabling operations to be carried on during the night, and when operating in
countries in which the sky continues to be overcast for considerable periods at a
time.
When it is considered that the whole has been exposed for a sufficient length of
time (the requisite duration usually only a few minutes of this part of the process
being determined by experience and practice) the copper plate is taken off, and
replaced for a short time over the spirit lamp, in order to prevent it from becoming
too sticky, and by means of a very fine brush the vitrifiable metallic powder, in a
state of impalpable dust, is sprinkled or dusted over it. This powder, which
constitutes the coloring enamel, is composed of metallic oxides and of fluxes,
adapted to the nature of the cerainic products, and the degree of heat to which they
are to be subjected. For example, the vitrifiable colours in powder, for quick fire,
are employed for common earthenware and reverberatory colours or porcelain
colors, also in a state of impalpable powder, are employed for products baked in a
muffle or porcelain kiln.
In laying on the powder with the brush the picture will be seen to develope
itself, and the thickness of the vitrifiable powder may be regulated (according to
the qualities of the metallic colours, and taking into consideration the subsequent
action, which will necessarily take place during the baking) either by removing
tones or by softening the contours, as will be well understood. This powdering
operation may moreover be repeated several times if necessary, the saine depending
on the duration of the exposure of the plate, which may itself have been insufficient,
the plate being placed at rest, and the powder laid on again with the brush, until⚫
the tints and half tints are all brought out.
When the picture is completely developed there is poured over the copper plate a
coating of well filtered collodion, composed of pyroxylin, ether, and alcohol, in about
the under mentioned proportions,-
Pyroxyline, say from about 10 to 12 parts by weight,
Ether,
Alcohol,
"
"
"
600
400
"
"
do.
do.
do.
do.

page_text: with the said enamel. The collodion is then carefully cut out round the frame by
means of a graver or otherwise and the frame removed. The picture when cut out
remains thus fixed, it is dried in the open air or at a gentle fire, and very fine and
well filtered oil of petroleum poured over the whole. Impurities, if any exist, may
be removed with a brush and the picture may be retouched with the same
vitrifiable powder mixed with essence of lavender. The picture being thus fixed
and dried the article may be placed in an oven in the usual manner of treating any
other description of painting on enamel or glaze, the mode and amount of baking
being moreover adapted to the composition of the vitrifiable colours employed in a
state of impalpable powder.
The employment of vitrifiable colours in powder which necessitate the exposure
to an intense heat may be dispensed with by simply sprinkling the picture with
impalpable charcoal powder, which is to be covered with a gelatine varnish. By
these means copies may be obtained which are capable of resisting the effects of
moisture and sufficiently durable.
It will be understood that the positive impressions upon glass before mentioned
may be replaced by ordinary photographs upon transparent paper, the process with
this paper being similar to that adopted with the impression upon glass, with the
exception that it requires to be exposed to the action of light for a longer period;
varying in proportion to the thickness or opacity of the paper. It is also necessary
that the pulp of which the said paper is made should be homogeneous and free
from impurities which would obstruct the luminous rays. The adhesion of the
bichromate sensitive coating to the paper may be prevented by ensuring the
dryness of the coating and employing paper either glazed or covered with a nitrate
varnish as for photographs, also by placing the paper picture between two plates of
very clear glass as thin as possible, this latter condition being essential to securing
a clear impression.
The plates of glass with the picture are fixed upon the copper plate by means of,
say, 3 or 4 small spring clamps, which prevent all slipping of the picture on the
sensitive coating during the operation of exposing it to the action of the light,
which is an important condition for obtaining a satisfactory result.
The process is carried out in a similar manner when engravings, lithographs, or
drawings upon paper are employed, such paper being made from pure pulp and
sufficiently thin.
Among the purposes to which this process is applicable may be enumerated the
following-Reproduction of all artistic works of the great masters, pictures,
drawings, monuments, photographs upon plates, medallions, vases of all shapes,
dishes, plates, and all ceramic products capable of being covered with an enamel or
glaze, whether the said glaze be transparent or opaque, and coloured in such a
manner as to form a ground, or whether it is uniformly opaque and of a plain
white colour.
In a similar manner pictures may be transferred to biscuits which are to be
subsequently covered with a transparent glaze. For this purpose it is necessary to
maintain the biscuits in a wet condition at the moment of performing the operation,
otherwise the collodion will contract, and no delay should take place in dipping the
article into the transparent glaze, otherwise this latter would not cover the picture
properly.
The advantage of operating upon products in the condition of biscuit consists in
the capability of employing bright colors, as the transparent coating which covers
them protects them from the action of the flame. If a delay is inevitable before t
effecting the dipping in the glaze it will be necessary to pour a thin film of
petroleum upon the picture with some siccative so as to ensure the picture at the
time of dipping being free from grease, which would occasion accidents in the
operation.
As the positive plate or proof undergoes no change or deterioration in the opera- 5
tion it may be reutilized an indefinite number of times, so that the impression on a
single plate or proof may be repeated or reproduced as often as desired. This

page_text: reproduction is obtained moreover with all the fidelity of which the photographic
art is capable, and the fineness of the detail only depends upon that of the picture
on the glass.
The baking which ultimately fixes the picture renders it by the act of fusion
completely unchangeable, for quick fire colors especially. The reproductions are
thus proof against injury from acids, moisture, and conflagrations.
This process by reason of the fineness of the details which may be obtained by it
is likewise applicable to the reproduction of photographs for industrial and other
purposes upon plates not susceptible of change or deterioration, as herein-before
described.
Having now described and particularly ascertained the nature of the said Inven-
tion, and the manner in which the same is or may be used or carried into effect,
I would observe in conclusion that what I consider to be novel and original, and
therefore claim as the Invention secured to me by the herein-before in part recited
Letters Patent is,―
First. Producing photographic images upon or ornamenting glass, or glazed, or
enamelled articles substantially in the manner and by the means herein-before
described.
Second. The application and use of a metal plate for the reception of a sensitive
film or coating which is acted upon by light passing through a superposed positive
impression, substantially as hercin-before described.
Third. The employment of a frame or holder constructed of flexible materials
which are insoluble in water for the purpose of transferring the picture to the glaze
or enamel, substantially as herein-before described.
In witness whereof, I, the said John Henry Johnson, have to this my Speci-
fication set my hand and seal, the Twenty-first day of February, One
thousand eight hundred and seventy-seven.
TAKERY
J. HENRY JOHNSON. (L.S.)