Improvements in Sensitized Papers, Cards, and other Materials Used for the Production of Photographic Prints from Negatives.
Year: 1899

page_text: Date of Application, 2nd Sent 1809
Complete Specification Left, 27th Apr., 1900-Accepted, 2nd June, 1900
Complete Specification Left, 27th Apr., 1900-Accepted, 2nd June, 1900
PROVISIONAL SPECIFICATION.
Improvements in Sensitized Papers, Cards, and other Materials Used
for the Production of Photographic Prints from Negatives.
We. JOHN EDWARD THORNTON, of Rokeby, Oldfield Road, Altrincham,
Cheshire, Manufacturer, and CHARLES FREDERICK SEYMOUR ROTHWELL, of
Worsley Mills, Worsley Street, Hulme, Manchester, Lancashire, Chemist, do
hereby declare the nature of this invention to be as follows:-
For producing photographic paper prints from negatives, it has been neces-
sary, after exposing the paper to light under a negative, to develop and fix the
image in separate solutions in the case of some papers, whilst in others it was
necessary to tone and fix the image either in separate solutions or in a com-
bined solution. These operations have always been troublesome, and often
uncertain, especially with amateur photographers, on account of the necessity
for carefully mixing the chemicals and preparing the solutions, and also the
necessity for exercising care in the quantities of each ingredient used for each
print, whilst the quantity of solution wasted through excess, or because of its
going bad from keeping, often cost more than the quantity actually used.
The object of this invention is to dispense with bottles of chemical solutions,
and with all the weighing out and mixing of chemicals, and with the waste
now incurred, and to provide printing papers cardboard, and other suitable
materials upon which prints can be readily finished off after printing. It has
no reference to pictures obtained in the camera, which are termed negatives.
In carrying out our invention we coat the back of our printing paper with
concentrated solution of the necessary chemicals incorporated with a soluable
cement or coating such as gum, starch, or the like, which can be easily applied
to the paper, and will become and keep dry, and yet which will readily dissolve
in and mix with water.
For development papers, such as gelatino-bromide of silver, gelatino-chloride
of silver, and the like we may use a developer only, but we prefer to use a com-
bined developer and fixer. After printing the paper is immersed in water, and
kept in motion until the chemical thoroughly dissolves, and then develops, fixes,
and completes the print, after which it may be well washed in running water
to remove the chemicals, and then dried as usual.
For print-out papers, such as gelatino-chloride, collodio-chloride, and the
like, we may use a combined toner and fixer, or if the toning chemical is incor-
porated with the sensitized coating (as is possible and sometimes done) we simply
apply the fixing chemical to the lack of the paper.
In cases where it is desirable to protect the coating of chemicals we may
cover the back of the paper by a separate piece of plain paper cemented thereto
by a soluble cement (such as gum for instance), so that the chemicals are en-
closed between and sealed by the two papers. The chemicals could of course
be applied to the backing paper instead of the printing paper.
It is absolutely essential that the back of the sensitized paper be rendered

page_text: waterproof before the application of the chemicals thereto, and also desirable
that the sealing paper should be airproof to better protect the chemicals from
the action of the atmosphere. The waterproofing can be done by coating with
celluloid or other. suitable waterproof varnish, but we prefer, however, to use
a product such as is obtained by treating or dissolving the zine or aluminium
salts of the fatty or resin acids (or a mixture of these salts) with a suitable vola-
tile solvent, such as benzole, coal-tar naptha, benzoline, or other similar light
hydrocarbon, and drying or solidifying the same in the presence of heated
air. This product has already been made the subject of an application for a
Patent in our joint names, dated February 25th 1899, and numbered 4237.
The following may be taken as examples of suitable preparations. They
may be made up in the form of a strong solution, with sugar or dextrine, and
then applied to the back of the waterproofed sensitized paper.
Improvements in Sensitized Papers, Cards, and other Materials Used
for the Production of Photographic Prints from Negatives.
We, JOHN EDWARD THORNTON, of Rokeby, Oldfield Road, Altrincham,
Cheshire, Manufacturer, and CHARLES FREDERICK SEYMOUR ROTHWELL, of
Worsley Mills, Worsley Street, Hulme, Manchester, Lancashire, Chemist, 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 follow-
ing statement:-
In the art or process of producing photographic prints from negatives upou
prepared paper by exposing the paper to light under the negative it has hitherto
been the universal practice to develop and fix the image in two separately
prepared solutions in the case of some papers whilst with other papers it has
been necessary to tone and fix the image either in separate solutions or in a
,single solution prepared from the combined chemicals.

page_text: These operations have always been troublesome and often uncertain especially
with amateur photographers on account of the necessity for carefully mixing
the chemicals and preparing the solutions and also the necessity for exercising
care in the quantities of each ingredient used for each print whilst the quantity
of solution wasted through excess or because of its going bad from keeping
often cost more than the quantity actually used.
The object of this invention is to dispense with bottles of chemical solutions
and with all the weighing out and mixing of chemicals and with the waste
now incurred and to provide printing papers cardboard and other suitable
materials upon which prints can be readily finished off after printing.
The invention has no reference to sensitive plates or films for use in the
camera nor to the pictures produced thereon which are termed negatives.
The invention consists essentially in coating the back of the printing paper
with a concentrated solution of the necessary chemicals to produce, when dis-
solved in water, a developing and fixing solution.
In carrying out the invention we prepare a concentrated solution of the
developing and fixing medium with a soluble cement or adhesive such as gum,
starch, dextrine sugar or the like, which can be easily applied to the surface
of the paper, will dry or set hard thereon, and be readily dissolved again when
immersed in water.
We prefer to prepare the medium as a combined developer and fixer but it
may be prepared and applied as a developer only, to certain classes of paper,
or it may be prepared as a combined toner and fixer, or as a fixing medium
only, according to the class of sensitive paper to which it is to be applied.
The following may be taken as examples of suitable preparations.

page_text: attached thereto such as paper, soluble gelatine, or other suitable material,
thus enclosing the chemical medium between the paper and the airtight cover-
ing, which will prevent the action of the air upon the developing medium and
will prevent it coming into contact with and damaging the adjacent sheet of
printing paper.
For development papers, such as gelatino-bromide of silver, gelatino-chloride
of silver and the like we may use a developer only, but we prefer to use a
combined developer and fixer.
For print-out papers, such as gelatino-chloride, collodio-chloride, and the
like we may use a combined toner and fixer, or if the toning chemical is incor-
porated with the sensitized coating (as is possible and sometimes done), we
simply apply the fixing chemical to the back of the paper.
In use, after the prepared sensitive paper has been printed in the ordinary
way, it is immersed in water, and kept in motion therein until the chemical
medium attached to the back completely dissolves. The solution thus produced
develops, fixes and completes the print, the paper being allowed to remain in
the solution any desired length of time. It is subsequently well washed in
running water to remove all trace of the chemical medium and dried in the
usual way.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that
what we claim is:-
1. A sensitive paper or other material for the production of photographic
prints from negatives prepared with a chemical medium attached thereto for
developing, fixing or toning the picture substantially as described.
2. A sensitive paper or other material for the production of photographic
prints from negatives prepared with a waterproof coating on the back and a
layer of developing, fixing or toning medium attached thereto substantially
as described.
3. A sensitive paper or other material for the production of photographic
prints from negatives prepared with a layer of chemical medium attached to the
back for developing, fixing or toning the picture protected by an airtight cover-
ing substantially as described.
4. A sensitive paper or other material for the production of photographic
prints prepared substantially as and for the purposes described.
Dated this 26th day of April 1900
Dated this 26th day of April 1900
WM. P. THOMPSON & Co.,
6, Bank Street, Manchester, Patent Agents.