IMPROVEMENTS IN PRODUCING FROM PHOTOGRAPHIC NEGATIVES, BLOCKS, OR PLATES SUITABLE FOR TYPOGRAPHIC SURFACE PRINTING
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I HENRY GARDNER of 166 Fleet Street in the city of London Patent Agent.
do hereby declare the nature of my said invention for "IMPROVEMENTS IN
PRODUCING FROM PHOTOGRAPHIC NEGATIVES, BLOCKS, OR PLATES SUITABLE FOR
TYPOGRAPHIC SURFACE PRINTING to be as follows:-
The object of this invention is attaching by any adhesive substance a film or
sheet of any material which has been impressed with the form of an engraved
surface capable of printing in a typographic press a series of marks producing the
effect of an even tint or shade, to a relief produced by photographic means, and the
rubbing or pressing the surface thus produced with some straight or plane surface
with the effect of increasing the size of the marks on the raised portions of the
relief and consequently rendering them capable of printing a series of marks
having the effect of a darker shade or tint than the rest, the surface produced
being thus capable of printing in a typographic press a series of marks large in the
darker portions of the picture which is intended to reproduce and smaller in the
lighter portions.
For the purpose of this invention I prepare a photographic relief in the following
manner.
Having allowed one ounce of gelatine to swell in sufficient quantity of water to
cover it I add one quarter of an ounce of sugar and dissolve the whole at a gentle
heat and then pour on boiling water sufficient to double the quantity of liquid
af.er which I sensitize the solution by adding from twenty to thirty drops of a
saturated solution of bichromate of potash. On a plate of glass of suitable size
I pour a sufficient quantity of this solution to float easily to the edges and set the
plate in a draughty situation sheltered from the daylight until the gelatine is dry.
I then expose the plate thus prepared to the rays of the sun under a negative of
the portrait or picture which is to be reproduced the exposure lasting about a
quarter of an hour.
In then place the plate in cold water and leave it to swell until the lightest
portions of the picture have swelled to the height of about one tenth of an inch.

page_text: J
In order to take a cast from the gelatine relief thus obtained I rub the surface of
the gelatine first with powdered alum and then with a lather of soap, wipe it clean
and pour on plaster of paris, which when set is easily removed. In the cast thus
formed the dark portions of the picture to be reproduced are represented by
elevations and the light portions by depressions. I then rub the surface of the
cast first with a small quantity of common gum solution and then with gold size
made of linseed oil boiled to a sticky consistency. The relief is then ready to
receive the film impressed with the form of an engraved surface.
This film is prepared as follows:-I take a sheet of tinfoil or any other material
which will readily take the form of any surface on which it is pressed and place it
on the surface of an engraved block of wood metal or any other suitable material.
The engraved block has raised lines, dots or other marks arranged regularly so as
to produce when printed from in an ordinary typographic surface printing press
the effect of an even shade or tint. The tinfoil or other material having been
placed on the surface of the block is covered with a piece of woolen cloth and
submitted to pressure until an exact impression of the engraved surface has been
communicated to it. I then remove it from the block and place it on the prepared
surface of the plaster cast the dots, lines or other marks being uppermost. A piece
of soft woolen or flannel cloth having been again placed above the tinfoil or other
material I subimit the wholo to a gentle pressure until it has taken the form of tlie
surface of the plaster cast yet without having the dots, lines or other marks
obliterated. The surface then presents the appearance of a series of raised
eminences of which the highest are situated on the raised portions of the plaster
cast that is to say, on the portions of the picture which are darkest; the middle
tints being partially raised and the lightest portions lying in the depressions.
I then gently rub the surface with any instrument having a smooth even surface,
such as the handle of an ordinary lead pencil laid flat and passed backwards and
forwards or a slab of glass metal or other material pressed gently on the raised
dots or lines or other marks. The effect is that those portions of the surface of the
tinfoil or other material which have the highest eminences receive the greatest
pressure and consequently the raised marks on these portions are most flattened
out; the intermediate elevations having the raised marks flattened in proportion
to their height. The pressure and rubbing are continued until on those portions
of the surface which.are intended to be capable in the finished block or plate, of
printing pure-black-or-the-darkest shade, the dots become merged into one another.
The surface thus produced is capable of being printed from but is not strong enough
to yield many impressions I therefore tako from it a cast either in plaster of paris
or in wax or other suitable material and make either a stereotype or an electrotype
in the ordinary manner.

page_text: "
I HENRY GARDNER of 166 Fleet Street in the city of London, Patent Agent,
do hereby declare the nature of the said invention for "IMPROVEMENTS IN
PRODUCING FROM PHOTOGRAPHIC NEGATIVES, BLOCKS OR PLATES SUITABLE FOR
TYPOGRAPHIC SURFACE PRINTING and in what manner the same is to be performed
to be particularly described and ascertained in and by the following statement :-
The object of this invention is attaching by any adhesive substance a film or
sheet of any material which has been impressed with the form of an engraved
surface capable of printing in a typographic press a series of marks producing
the effect of an even tint or shade to a relief produced by photographic means
and the rubbing or pressing the surface thus produced with some straight or
plane surface with the effect of increasing the size of the marks on the raised
portions of the relief and consequently rendering them capable of printing a series
of marks having the effect of a darker shade or tint than the rest, the surface
produced being thus capable of printing in a typographic press a series of marks
large in the darker portions of the picture which it is intended to reproduce and
smaller in the lighter portions.
For the purpose of this invention I prepare a photographic relief in the following
manner. Having allowed one ounce of gelatine to swell in sufficient water to
cover it I add one quarter of an ounce of sugar and dissolve the whole at a gentle
heat and then pour on boiling water sufficient to double the quantity of liquid after
which I sensitize the solution by adding from twenty to thirty drops of a saturated
solution of bichromate of potash. On a plate of glass of suitable size I pour
a sufficient quantity of this solution to float easily to the edges and set the plate
in a draughty situation sheltered from the daylight until the gelatine is dry. I then
expose the plate thus prepared to the rays of the sun under a negative of the
portrait or picture which is to be reproduced the exposure lasting about a quarter
of an hour I then place the plate in cold water and leave it to swell until the
lightest portions of the picture have swelled to the height of about one tenth of
an inch. In order to take a cast from the gelatine relief thus obtained I rub the
surface of the gelatine first with powdered alum and then with a lather of soap,
wipe it clean and pour on plaster of paris which when set is easily removed. In
the cast thus formed the dark portions of the picture to be reproduced are repre-
sented by elevations and the light portions by depressions. I then rub the surface
of the cast first with a small quantity of common gum solution and then with gold
size made of linseed oil boiled to a sticky consistency. The relief is then ready to
receive the film impressed with the form of an engraved surface. This film is
prepared as follows:-I take a sheet of tinfoil or any other material which will
readily take the form of any surface on which it is pressed and place it on the
surface of an engraved block of wood metal or any other suitable material. The
engraved block has raised lines, dots or other marks arranged regularly so as to
produce when printed from in an ordinary typographic surface printing press the
effect of an even shade or tent. The tinfoil or other material having been placed
on the surface of the block is covered with a piece of woollen cloth and submitted
to pressure until an exact impression of the engraved surface has been communicated
to it. I then remove it from the block and place it on the prepared surface of the
plaster cast the dots, lines or other marks being upper-most. A piece of soft
woollen or flannel cloth having been again placed above the tinfoil or other material
I submit the whole to a gentle pressure until it has taken the form of the surface

page_text: of the plaster cast yet without having the dots, lines or other marks obliterated.
The surface then presents the appearance of a series of raised eminences of which
the highest are situated on the raised portions of the plaster cast that is to say on
the portions of the picture which are darkest the middle tints being partially raised
and the lightest portions lying in the depressions I then gently rub the surface
with any instrument having a smooth even surface such as the handle of an ordinary
lead pencil laid flat and passed backwards and forwards or a slab of glass, metal or
other material pressed gently on the raised dots or lines or other marks. The effect
is that those portions of the surface of the tinfoil or other material which have the
highest eminences receive the greatest pressure and consequently the raised marks
on those portions are most flattened out: the intermediate elevations having the
raised marks flattened in proportion to their height The pressure and rubbing are
continued until on those portions of the surface which are intended to be capable
in the finished block or plate, of printing pure black or the darkest shade, the dots
become merged into one another. The surface thus produced is capable of being
printed from but is not strong enough to yield many impressions I therefore take
from it a cast either in plaster of paris or in wax or other suitable material and
make either a stereotype or an electrotype in the ordinary manner.
If the type metal or copper or other surface so produced does not print a
sufficiently dark picture either in whole or in part I rub the surface with a flat
piece of wood to which a piece of emery cloth has been attached or with any
other flat or straight instrument suitable for grinding, filing or pressing metals.
Having now particularly described and ascertained tho nature of the said
invention and in what manner the same is to be performed I declare that I claim
as the improvements in producing from photographic negatives, blocks or plates
suitable for typographic surface printing, attaching by any adhesive substance
a film or sheet of any material which has been impressed with the form of an
engraved surface capable of printing in a typographic press a series of marks
producing the effect of an even tint or shade to a relief produced by photographic
means, and the rubbing or pressing the surface thus produced with some straight
or.plane surface with the effect of increasing the size of the marks on the raised
portions of the relief and consequently rendering them capable of printing a series
of marks having the effect of a darker shade or tint than the rest, the surface
produced being thus capable of printing in a typographic press a series of marks
large in the darker portions of the picture which it is intended to reproduce and
smaller in the lighter portions as set forth.