LMPROVEMENTS IN OBTAINING PRINTING SURFACES BY PHOTOGRAPHY
Year: 1884

page_text: I JOSEPH BROWN of 43 Halsey Street Cadogan Square Chelsea Gentleman do
hereby declare the nature of the said invention for "LMPROVEMENTS IN OBTAINING
PRINTING SURFACES BY PHOTOGRAPHY to be as follows:-
The following description of the process by which I effect the objects of my
invention will clearly illustrate the modus operandi, which is as follows:
'
Having first selected a hand drawing, print, engraving or photograph which it is
the intention by this process to reproduce on a flat or other surface of steel iron
copper, zinc, brass, bronze and the more precious metals, I then prepare a solution
of some suitable gum to which is added bichromate of ammonia or potash in the
proportions as example of about 3 of the gum to of the bichromate of potash or
ammonia these quantities would vary in accordance with the temperature at the
time of operating.
In certain cases it may be advantageous to add to these ingredients albumen or
fine soap in the proportions of about 5% to the other ingredients.
I then procure either a plate or cylinder of any of the metals referred to, on the
surface of which I apply my solution, which has the effect of sensitizing it, and
rendering its surface sensitive to the action of light, I next take the selected
drawing or photograph and place it face downwards on the sensitized surface, and
then submit the whole to the action of light, and by this means have the image
transferred or imprinted on the sensitized surface of the gum sensitizer on the
plates surface, I now proceed to develope this picture by means of either a dabber
or a roller with a bituminous or acid resisting varnish after which the plate is
immersed in a bath of either spirits of wine or methylated spirit, which has the
effect of disintegrating all those parts that have not been affected by the light
whilst at the same time hardening or coagulating those parts that have been so
affected.
The plate in this condition is now ready for the action of the various mordants
to which it is submitted and which may be either by electric action or any of the
acids ordinarily employed and suitable to the metal to which they are applied the
action of the mordant being allowed to operate until the requisite depth has been
bitten into the plate.
Dated this eighth day of March 1884

page_text: °
I JOSEPH BROWN of 43 Halsey Street, Cadogan Square Chelsea, Gentleman do
bereby declare the nature of the said invention for IMPROVEMENTS IN OBTAINING
PRINTING SURFACES BY PHOTOGRAPHY, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
.
'
The following description of the process by which I effect the objects of my
invention will clearly illustrate the modus operandi, which is as follows:
Having first selected a hand drawing, print; engraving, or photograph, which it
is the intention by this process to reproduce on a flat or other surface of steel,
iron, copper, zinc, brass, bronze, and the more precious metals.
I then prepare a solution of some suitable gum, to which is added bichromate
of ammonia or potash, in the proportions as example of about 3 of the gum to of
the bichromate of potash or ammonia; these quantities would vary in accordance
with the temperature at the time of operating.
In certain cases it may be advantageous to add to these ingredients albumen, or
fine soap, in the proportions of about 5% to the other ingredients.
°
I then procure either a plate, or cylinder of any of the metals referred to; on the
surface of which I apply my solution, which has the effect of sensitizing it, and
rendering its surface sensitive to the action of light.
I next take the selected drawing or photograph and place it face downwards on
the sensitized surface, and then submit the whole to the action of light, and by
this means have the image transferred or imprinted on the sensitized surface of the
gum sensitizer on the plates' surface.
I now proceed to develop this picture by means of either a dabber or a roller
with a bituminous or acid resisting varnish, after which the plate is imipersed in a
bath of either spirits of wine or methylated spirit, which has the effect of
disintegrating all those parts that have not been affected by the light, whilst ai
the same time hardening or coagulating those parts that have been so affected.
The plate in this condition is now ready for the action of the various mordants,
to which it is submitted, and which may be either by electric action, or any of the
acids ordinarily employed, and suitable to the metal to which they are applied, the
action of the mordant being allowed to operate until the requisite depth has been
bitten into the plate.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1st The process herein referred to for the reproduction of hand drawings, prints,
or engravings, such process consisting essentially in the method of sensitizing
a flat or cylindrical metal surface, by means of a gum sensitizer composed
of a solution of suitable gum to which is added bichromate of ammonia or
potash in the proportion of of gum to of the bichromates, such quantities
varying in proportion in accordance with the temperature at the time of
operation, adding to these ingredients under certain circumstances about

page_text: 2nd The method of developing the drawing, print, or engraving, by the application
of a bituminous ink or varnish, and the further development of the same
by means of spirits of wine or methylated spirits.
3rd In the method of mordantizing the plates surface or surfaces as and for the
purposes herein set forth in combination with the other parts forming the
claim.