IMPROVEMENTS IN REPRO- DUCING PHOTOGRAPHS BY PRINTING AND IN PRODUCING PRINTING BLOCKS OR ROLLERS THEREFOR
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I, LUDWIG HERMANN PHILIPPI of Steinhoeft, No 3 Hamburg, Germany Architect,
do hereby declare the nature of my invention for IMPROVEMENTS IN REPRO-
DUCING PHOTOGRAPHS BY PRINTING AND IN PRODUCING PRINTING BLOCKS OR
ROLLERS THEREFOR to be as follows:-
The object of this invention is to produce pictures by means of a number of
printing blocks, which have been all obtained by means of the same photographical
positive or negative, but which all differ from each other in consequence of a
relatively more or less long exposure to the influence of light, and the impressions
of which are superposed or are placed one above the other on the material, whereon
the reproduction of the original has to appear.
In carrying my invention into practice, I make use of a photographical negative
or positive produced upon suitable transparent or translucent material such as
glass, gelatine et cetera. I place such negative or positive on a plate of metal, glass,
stone or other suitable material which is covered with a suitable layer of such
substances as are changeable in their solubility under the influence of light as, for
example, asphaltum, chromatized gelatine and the like, and insert between both
or place upon both a transparent or translucent plate or foil or surface provided
with parallel lines.
•
Then I expose the sensitized coating until all shades of the photographical
positive or negative but the darkest and consequently the most impermeable,
partly interrupted by the lines of the hatched plate or foil, are transferred
thereon. Preferably I place the photographical positive or negative in such a
manner as to dispose light and shade in the same manner as the original shows
them, but such position also may be varied according to convenience. By washing
out afterwards the sensitized coating respectively in a convenient manner by
etching the plate beneath it or by treating it with a sand-blast a printing block
is produced, in which all spots not exposed to the influence of the light are washed
out respectively etched or ground away, while the rest of the plate is covered with
a system or succession of parallel lines corresponding with the design of the
inserted or applied plate, surface, or foil. By making an impression with such
block, only the parallel lines will appear on the material to be printed.

page_text: In the like manner I make some more printing blocks by giving the inserted
plate at each exposure a turn of part of the circle and by reducing the time of
exposure at each exposure (when supposing there to be an equal force of light
. acting, an equal or uniform transparency or translucency of the transparent or
translucent materials and an equal sensibility of the sensitized layer to exist at
each exposure); thus printing blocks are produced with less and less hatched
surfaces. In most cases four printing blocks will suffice, their production
requiring a turn of 45 degrees of the hatched surface, plate, or foil at each
exposure.
I then make impressions with such printing blocks on paper; cloth or other
suitable material by placing properly the guide-marks of the blocks. Thus pictures
are produced; in which the shades are composed of crossed lines, and such crossing
lines will be the more frequent according as the shado is darker, while the clearest
part of the picture will not show any lines at all.
In lieu of parallel lines on the transparent or translucent plate or foil, I also
make use of such other design with such repetitions of figures or marks as the
occasion renders desirable and I also vary the designs for the different blocks or
I insert two or more plates or foils with corresponding designs but in different
position or with designs differing from each other. Any suitable tissue of wiro,
thread or other fabric or surface or perforated sheets of metal, wood, paper or
similar material may equally be employed instead of the hatched transparent or
translucent plate or foil provided the light can sufficiently operate.
By the same process I also produce curved blocks or printing rollers; -but in
such case I make use of photographical positives or negatives and of foil (either
hatched or otherwise provided with designs) both produced on flexible transparent
or translucent material as gelatine-paper or sheet, tracing-cloth or other suitable
material; or instead of or with the hatched foil or surface I employ one or other
of the above mentioned tissue or perforated material.
'When impressions are made with blocks or rollers made according to my
invention on transparent or translucent material and the printed plates or foils are
placed above each other, transparent or translucent pictures are produced with the
described crossing of lines; and when made on sufficiently transparent and thin
material, such pictures may be used for making a printing block or roller, which
will show all fineness or effect of the crossing.

page_text: 1 LUDWIG HERMANN PHILIPPI of Hamburg Germany Architect do hereby
declare the nature of my invention for IMPROVEMENTS IN REPRODUCING PHOTO-
GRAPHS BY PRINTING, AND IN PRODUCING PRINTING BLOCKS OR ROLLERS THEREFOR,
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 to produce pictures by means of a number of
printing blocks, which are all obtained by means of the same photographical
positive or negative, but all differ from each other in consequence of a relatively
more or less long exposure to the influence of light, and the impressions of which
are placed one above the other on the material, whereon the reproduction of the
original has to appear.
To carry my invention into practice, I make use of a photographical negative or
positive produced on suitable transparent or translucent material such as glass,
gelatine et cetera. I place such negative or positive on a plate of metal, glass,
stone or other suitable material which is covered with a layer of such substances
which are changeable in their solubility through the influence of light as, for
example, asphaltum, chromatized gelatine and the like, and insert between both or
place upon both a transparent or translucent plate or foil provided with parallel
lines.
Then I expose the sensitized coating until all shades of the photographical
positive or negative but the darkest and consequently the most impermeable, partly
interrupted by the lines of the hatched plate or foil, are transferred thereon.
Preferably I place the photographical positive or negative in such a manner as to
dispose light and shade in the same manner as the original shows them, but such
position also may be varied according to convenience. By washing out afterwards
the sensitized coating respectively by etching the plate beneath it or by treating it
with a sand-blast a printing block is produced, in which all spots not exposed to
the influence of the light are washed out respectively etched or ground away, while
the rest of the plate covered with a system of parallel lines corresponding with
the design of the inserted plate or foil. By making an impression with such block,
only the parallel lines will appear on the material to be printed.
In the like manner I make some more printing blocks by giving the inserted'
plate at each exposure a turn of a part of the circle and by reducing the time of
exposing at each exposure (when supposing an equal force of the acting light, an
equal transparency or translucency of the transparent or translucent materials and
an equal sensibility of the sensitized layer to exist at each exposure); thus printing
blocks are produced with less and less batched surfaces. In the most cases four
printing blocks will suffice thus requiring a turn of 45 degrees of the hatched
plate or foil at each exposure.
I then make impressions with such printing blocks on paper, cloth or other
suitable material by placing properly the guide-marks of the blocks. Thus pictures
are produced, in which the shades are composed of crossed lines, and such crossing will

page_text: "
be as more frequent, as the shade is darker, while the clearest part of the picture
does not show any lines at all.
•
In lieu of parallel lines on the transparent or translucent plato or foil, I also
make use of any other design with repeated figures; I also vary with the designs.
for the different blocks or I insert two or more plates or foils with equal, designs
but in different position or with designs differing from each other. Any suitable
tissue of wire, thread et cetera or perforated sheets of metal, wood, paper or similar
material may equally be employed instead of the hatched transparent or translucent
plate or foil.
By the same process I also produce curved blocks or printing rollers; but in
such case I make use of photographical positives or negatives and of foil (either
hatched or otherwise provided with designs) both produced on flexible transparent
or translucent material as gelatine-paper, tracing-cloth or other suitable material; or
instead of the hatched foil I employ also the above mentioned tissue or perforated.
material.
When impressions are made with blocks or rollers made according to my
invention on transparent or translucent material and when the printed plates or
foils are placed above each other, transparent or translucent pictures are produced
with the described crossing of lines; when made on sufficiently transparent and
thin material, such pictures may be used for making a printing block or roller,
which shows all fineness of the crossing.
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
The method of producing pictures by means of a number of printing-blocks,
which are all obtained by means of the same photographic positive or negative,
but all differ from each other in consequence of a relatively more or less long
exposure to the influence of light and the impressions of which are placed one
above the other on the material whereon the reproduction of the original has to
Dated this 1st day of July 1885.
W. BROOKES & SON,
55 & 56, Chancery Lane, London,
Agents for the said Ludwig Hermann Philippi.