IMPROVEMENTS IN METHODS OF PRODUCING PRINTING-BLOCKS BY MEANS OF PHOTOGRAPHY
Year: 1884

page_text: I, WALTER BENTLEY WOODBURY of South Norwood in the County of Surrey
do hereby declare the nature of my invention for "IMPROVEMENTS IN METHODS
OF PRODUCING PRINTING-BLOCKS BY MEANS OF PHOTOGRAPHY to be as follows:-
ور
My invention relates to surface blocks by the aid of which typographic prints
may be obtained in the ordinary printing press and it has for its object novel
methods of giving to photographic negatives or positives the necessary qualities to
produce from them such surface printing blocks.
These qualities have usually been obtained by breaking up the continuous half-
tone of the negative or positive, produced in the ordinary way by photography,
into a series of lines, simple or crossed, dots or grains similar to that produced by a
lithographic stone or by effects similar to network or gauze.
From negatives or positives so produced printing blocks have heretofore been
obtained either by making reliefs in the well known way, and pressing such
reliefs into the surface of metal, or by transferring impressions to zinc and then
etching, also by exposing negatives so produced over a sheet of zinc covered with a
substance having the property of becoming insoluble by the action of light, such
as bitumen, or gelatine and bichromate of potash, and after removing the soluble
parts etching the parts left bare. These processes are and have been for some time
in ordinary use, and my invention consists in new or improved methods for the
production of negatives or positives suitable for the purposes above described..
In order to put my invention in operation, I procure a series of negatives or.
positives from such objects as fine ruled lines, netting, gauze, dots, or a print from
a grained stone.
I use these as "resists" from which I make in the ordinary way what is well
known as a carbon transparency and I transfer the same by the ordinary method
to the negative or positive and by then washing away the soluble portions I give
the necessary qualities.
Or sometimes I make a photolithographic transfer and I transfer the same to
the negative or positive, and if sufficient density is not obtained, I dust bronze or
other opaque powders over the image, so increasing it in force.
In another method which I sometimes adopt, by means of what is known as the
dusting process I. coat a sheet of glass with a compound of gelatino or albumen,

page_text: grape sugar, and bichromate of potash, and after exposure under a negative or
positive I sift over it suitable granular powders, or the material used for flocking
paper, thus producing a grain negative or positive suitable for the purposes already
described, or I coat a negative or positive with the same solution and I treat it in
the same way as the plain glass.
Or sometimes by means of what is well known as the Woodbury process I make
a relief image from the combination of the negative or positive and any of the
various resists mentioned and having obtained a suitable relief image by any of the
above mentioned processes which are well known and to which I make no claim,
by rolling or other convenient pressure I make a reverse relief of the same in a
sheet of fine cardboard, to which has been attached a sheet of transfer paper;-this
image I ink over carefully with an ink roller and after detaching the transfer paper
which may be temporarily attached to the card by means of indiarubber solution
I transfer in the ordinary way the image so produced to zinc for etching or to
stone for lithographing.
Dated thin 9th dow´of Wahutu 1001

page_text: "
I WALTER BENTLEY WOODBURY, of South Norwood, in the County of Surrey
do hereby declare the nature of my invention for "IMPROVEMENTS IN METHODS
and in what
FOR PRODUCING PRINTING BLOCKS BY MEANS OF PHOTOGRAPHY
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:—
My invention relates to surface blocks by the aid of which typographic prints.
nay be obtained in the ordinary printing press and it has for its object more
especially novel methods of giving to photographic negatives or positives the
necessary qualities to produce from them such surface printing blocks.
These qualities have usually been obtained by breaking up the continuous half-
tone of the negative or positive, produced in the ordinary way by photography,
into a series of lines, simple or crossed dots, or grains, similar to that produced by
a lithographic stone or by effects similar to network or gauze. From negatives or
positives so produced printing blocks have heretofore been obtained either by
making reliefs in the wellknown way, and pressing such reliefs into the surface
of metal, or by transferring impressions to zinc and then etching, also by exposing
negatives so produced over a sheet of zinc covered with a substance having the
property of becoming insoluble by the action of light, such as. bitumen, or gelatine
and bichromate of potash, and after removing the soluble parts etching the parts
left bare. These processes aro and have been for some time in ordinary use, and
my invention consists more especially in new or improved methods for the
production of negatives or positives suitable for the purposes above described.
In order to put my invention in operation I procure a series of negatives or
positives from such objects as fine ruled lines, netting, gauze, dots, or a print from
a plain stone.
I use these as "resists from which I make in the ordinary way what is well
known as a carbon transparency and I transfer the same by the ordinary method
to the negative or positive and by then washing away the soluble portions I give
the necessary qualities.
Or sometimes I make a photo-lithographic transfer and I transfer the same to
the negative or positive and if sufficient density is not obtained, I dust bronze or
other opaque powders over the image, so increasing the force.
In another method which I sometimes adopt, by means of what is known as the
dusting process I coat a sheet of glass with a compound of gelatine or albumen,
grape sugar, and bichromate of potash, and after exposure under a negative or
positive I sift over it suitable granular powders, or the material used for flocking
paper, thus producing a grain negative or positive suitable for the purposes already
described, or I coat a negative or positive with the same solution and I treat it in
the same way as plain glass.
Or sometimes by means of what is well known as the Woodbury process I make
a relief image from the combination of the negative or positive and any of the
various resists mentioned, and having obtained a suitable relief image by any of the
above mentioned processes which as herein before explained are well known and to
which I make no claim, by rolling or other convenient pressure I make a reverse
relief of the same in a sheet of fine cardboard to which has been attached a sheet of
transfer paper, and this image I ink over carefully with an ink roller and (after
detaching the transfer paper which may be temporarily attached to the card by
means of indiarubber solution) I transfer in the ordinary way. the image so pro-
duced to zinc or other metal or material for etching or to stone for lithographing.

page_text: 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
1. The method of producing a printing block by transferring a suitable carbon
transparency, obtained from "resists' having grained surfaces of the kind described,
to a negative or positive, substantially as described.
2. The method of producing a printing block by dusting a suitable powder or
material upon an ordinary photographic negative or positive, substantially as
described.
+
3. The method of producing such negative or positive by dusting a suitable
powder or material upon a film sensitive to light, substantially as described.
4. The method of producing a printing block by pressing a relief, photographic
image into a sheet of cardboard having a sheet of transfer paper attached to it,
which sheet of transfer paper after having been inked is removed to a metal or
other surface which is then etched, substantially as described.
Dated this 8th day of November 1881