Improvements in the Production of Tablets or Transparencies Bearing Business Announcements, Advertisements, Decorative or other Matter, by the Aid of Photography.
Year: 1894

page_text: Date of Application, 3rd Apr., 1894-Accepted, 25th May, 1894
COMPLETE SPECIFICATION.
Improvements in the Production of Tablets or Transparencies
Bearing Business Announcements, Advertisements, Decorative
or other Matter, by the Aid of Photography.
We, EDWARD JOSIAH TOBIN of No. 254 George Street in the City of Sydney
and Colony of New South Wales, Merchant, and FRANK GEORGE BEMENT of
No. 166 Paddington Street Sydney, in the said Colony, Photo and Process
Engraver, 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 following statement :-
This invention relates to prints produced by the actinic or chemical action of
light upon prepared or sensitised surfaces which surfaces are subjected to more or
less further treatment. This invention has been devised in order to produce actinic
prints upon glass in a cheap and effective manner and it is especially applicable to
the production of show cards business announcements advertisements and decora-
tions of all kinds which may by this invention be produced economically and of
attractive nature.
The improved actinic prints may be made of any color in which lithographic
transfer ink is made and they are superposed on the back of glass sheets which
may be used as a transparency or may have a backing of mercury or of color or
they may have an independent mechanically attached backing.
In producing our improved actinic prints we first prepare a solution as
follows
of potash OF OF DIchromate of
ammonium
to 40 gramus
the quantities being varied according to the weather and those peculiarities of
action which experience alone teaches must be provided for. The solution being
properly mixed and thoroughly filtered is poured over the chemically clean surface
of the glass and the thus coated glass dried in a dark room. The dried sensitised
glass is now exposed in an ordinary photo-engravers printing frame under a
transparent negative or positive for say two minutes or such time as experience and
judgment may determine. The exposed glass removed from the frame in the dark
room is then carefully rolled up on the film side with lithographic transfer ink
until a film of ink is evenly spread over its coated surface. Being now immersed
in a cold bath the picture or print is developed and those portions of the albumen
which during exposure were protected by the lines or tones of the negative or
positive from the actinic action of light are washed away using gently a pledget of
say cotton wool.
The picture or print is after washing seen on the glass in black
or color of the ink with all necessary detail as required. The picture or print thus
produced is thoroughly dried and backed up by the ordinary silvering process as in
producing mirrors or is colored or it is varnished for using as a transparency or
with a separate backing diaphragm.
Although we have given in the formula the substances and materials which we
have found best adapted for effectively carrying out our invention and also the most
appropriate relative quantities thereof yet it is to be distinctly understood that we
do not confine ourselves to such material nor to the exact proportions mentioned
within reasonable limit for as is well known by photo and process engravers there
TD 077

page_text: may in place of the albumen be substituted other substances and compounds such
as gelatine and like glutinous matters which will produce a print capable of being
rolled up and developed and in place of the bichromate there might be substituted
other salts and substances capable of sensitising an albuminous or glutinous film.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
First. Improved actinic prints consisting of a picture or lettering &c. developed
on a sensitised film on glass after exposure to light under a transparent negative or
positive and after inking or rolling up with lithographic transfer or greasy ink by
washing in cold water substantially as herein described and explained.
Second. Improved actinic prints consisting of a picture or lettering &c.
developed on a sensitised film on glass after exposure to light under a transparent
negative or positive and after inking or rolling up with lithographic transfer or
greasy ink by washing in cold water and then silvered or coated with mercury or
colored as a backing substantially as herein described and explained.
Third. Improved method of producing actinic prints consisting in all of the
following steps namely first fixing a seusitised film consisting of albumen or like
glutinous matter water and bichromate of potash or bichromate of ammonium or
like salts or sensitising materials on glass secondly exposing the dried coated glass
under a transparent picture &c. to light thirdly rolling or inking up the sensitised
film with lithographic transfer greasy ink and fourthly developing in water and
washing the unaffected parts of the film away substantially as herein described and
explained.
Fourth. Improved method of producing actinic prints consisting of the steps set
out in the preceding claim and of silvering or coating with mercury the developed
film on the glass or coloring the same substantially as herein described and
explained.
Dated this Twenty-sixth day of February One thousand eight hundred and
ninate from