IMPROVEMENTS IN OBTAINING PROOFS OR IMPRESSIONS FROM PRINTING SURFACES PRODUCED BY PHOTOGRAPHY, AND ALSO IN OBTAINING SUCH PRINTING SURFACES
Year: 1870

page_text: LETTERS PATENT to Frederick Richard Window, of Baker Street, .
-
Portman Square, in the County of Middlesex, Photographer, for
the Invention of "IMPROVEMENTS IN OBTAINING PROOFS OR IMPRESSIONS
FROM PRINTING SURFACES PRODUCED BY PHOTOGRAPHY, AND ALSO IN OBTAINING
SUCH PRINTING SURFACES."
Sealed the 10th February 1871, and dated the 16th August 1870.
PROVISIONAL SPECIFICATION left by the said Frederick Richard
Window at the Office of the Commissioners of Patents, with his
Petition, on the 16th August 1870.
I, FREDERICK RICHARD WINDOW, of Baker Street, Portman Square,
5 in the County of Middlesex, Photographer, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN OBTAINING PROOPS OR IM-
PRESSIONS FROM PRINTING SURFACES PRODUCED BY PHOTOGRAPHY, AND ALSO IN
OBTAINING SUCH PRINTING SURFACES," to be as follows, that is to say :-
It is well known that various processes have been devised for obtaining
o metallic printing plates or surfaces in intaglio and in relief, and also
for obtaining surfaces for the same purpose on stone and upon gelatine

page_text: or other colloids. Many of the printing plates or surfaces so produced
yield satisfactory results when the design or subject is in line or in coarse
grain or stipple, but they fail to give satisfactory results when the design
or subject is in graduated tints, like an ordinary photograph, such proofs
being usually deficient in delicacy or perfect gradation in the half
tones, or deficient in strength and vigour in the shadows.
Now the first part of my Invention consists in an improved mode of
obtaining proofs or impressions from the plates or surfaces obtained by
photographic agency, of whatever kind or nature such plate may be, by
which I am enabled to produce a considerable degree of half tone
combined with great vigour in the subject to be reproduced. I effect
this by producing two or more plates instead of one from the same
negative, each of which plates has received a sufficient degree of exposure.
Thus I divide the subject in graduated tones into an imaginary series
of "flat tints," and if the process be one which merely yields a surface
giving a flat tint or impression I form as many plates as I have
assumed the subject to have tints, each plate having register marks
obtained directly from the negative; these plates are printed in suc-
cession in a more or less transparent ink of a depth calculated to give the
requisite tint, and as each plate contains different proportions of the
subject, the first containing the whole of the subject and the last only
the dark touches to form the deepest shadows, the whole subject is
ultimately produced with a degree of delicacy proportionate to the number
of surfaces employed. When the process employed is capable of yielding
surfaces which give a certain degree of half tone or impression much
fewer surfaces are necessary as each surface furnishes several of the
imaginary tints into which the subject is assumed to be divided. The
same principle is also applicable to the production of proofs in color by
using more surfaces and stopping out from each or from the negative
which produces them the colours complementary to that wished to be
produced. Thus if it be desired to print blue, or colours which contain
blue, all the parts of the picture which do not contain this colour must
be stopped out, and so on for each elementary colour and its composites.
The second part of my Invention consists in an improved mode of
obtaining printing surfaces on stone or zinc. I effect this by printing a
by means of a negative a positive image of the subject to be reproduced
in a compound which will form a resist upon the stone and which will
absorb moisture from the atmosphere, such for instance as a mixture of

page_text: albumen and honey, or gum and honey rendered sensitive by a chromate:
After exposure I allow this mixture to absorb moisture in the parts
not exposed to light, which then become sticky and adhere to the stone.
when the exposed proof is laid down upon it and submitted to pressure.
Or I print a negative image on gelatine or other colloid from the subject
itself or from a positive obtained from the negative of the subject, and
after printing I lay down the insolated proof upon stone after wetting it
and scraping out the air and superfluous moisture. I then wash away
the parts not acted upon by light. The stone supporting the negative
image so obtained is washed in a solution of alum and allowed to dry,.
when dry it is inked up in the usual way, the gelatine image is removed
by water and a sponge, and the fatty image remaining is treated in the
usual way for lithographic printing.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frederick Richard Window in the Great Seal
Patent Office on the 16th February 1871.
'
TO ALL TO WHOM THESE PRESENTS_SHALL COME, I, FREDERICK
RICHARD WINDOW, of Baker Street,: Portman Square, in the County of.
Middlesex, Photographer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent bearing date the Sixteenth day of August, in the year
of our Lord One thousand eight hundred and seventy, in the thirty
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Frederick Richard Window,. Her special
licence that I, the said Frederick Richard Window, my executors,
administrators, and assigns, or such others as I, the said Frederick
Richard Window, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might.
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS. IN OBTAINING PROOFS OR IMPRESSIONS FROM PRINTING
SURFACES PRODUCED BY PHOTOGRAPHY, AND ALSO IN OBTAINING SUCH PRINTING
SURFACES," upon the condition (amongst others) that I, the said Frederick
Richard Window, my executors or administrators, by an instrument in
'
:

page_text: writing under my, or their, or one of their hands and seals, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Frederick Richard Window, do
hereby declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement:-
It is well known that various processes have been devised for obtaining
metallic printing plates or surfaces in intaglio and in relief, and also for
obtaining such surfaces upon stone and upon gelatine or other colloids
by photography. Many of the printing plates or surfaces so produced
yield satisfactory results when the design or subject is in line or in
coarse grain or stipple, but they fail to give satisfactory results when
the design or subject is in graduated tints, like an ordinary photograph,
such proofs being usually deficient in delicacy or perfect gradation in the
half tones or deficient in strength and vigour in the shadows.
Now the first part of my Invention consists in an improved mode of
obtaining proofs or impressions from the plates or surfaces obtained by
photographic agency, of whatever kind or nature such plates may be,
and by which mode I am enabled to produce a considerable degree of
half tone combined with great vigour in the subject to be reproduced.
I carry out the first part of my Invention by producing two or more
plates instead of one from the same negative, each of which plates has
received a sufficient degree of exposure. By this means I divide the
subject in graduated tones into an imaginary series of "flat tints"; and
if the process be one which merely yields a surface giving a flat tint or
impression I form as many plates as I have assumed the subject to have
'tints, each of such plates having register marks obtained directly from
the negative; these plates are printed in succession in a more or less
'transparent ink of a depth calculated to give the requisite tint; and as
each plate contains different portions of the subject, the first containing
the whole of the subject, and the last only the dark touches to form
only the deepest shadows, the whole subject is ultimately produced with
a degree of delicacy proportionate to the number of surfaces employed.
When the process employed is susceptible of yielding surfaces which
give a certain degree of half tone or impression a smaller number of

page_text: surfaces is necessary, as each surface furnishes several of the imaginary
tints into which the subject is assumed to be divided. An analogous
process is also applicable to the production of proofs in color by using
more surfaces, and stopping out from each or from the negative which
produces them the colors complementary to the color it is wished to
produce. Thus if it be desired to print blue, or colors which contain
blue, all the parts of the picture which do not contain this colour must
be stopped out, and so on for each elementary colour and its composites.
The second part of my Invention consists in an improved mode or
improved modes of obtaining printing surfaces on stone or zinc. I effect
this by printing, by means of a negative, a positive image of the subject
to be reproduced in a compound which will form a resist upon the
stone, and which will absorb moisture from the atmosphere, such, for
instance, as a mixture of albumen and honey, or gum and honey,
rendered sensitive by a chromate, and spread upon paper. After exposure
I allow this mixture to absorb moisture in the parts not exposed to
light, which then becomes sticky and adheres to the stone, when the
exposed proof is laid down upon it and submitted to pressure. Or I
print a negative image on gelatine or other analogous colloid from the
subject itself, or from a positive obtained from the negative of the
subject, and after printing I lay down the insulated proof upon a stone
or zinc plate, after wetting it and scraping out the air and superfluous
moisture; I then wash away the parts not acted on by light. The stone
supporting the image so obtained is washed in a solution of alum and
allowed to dry; when dry it is inked up in the usual way, the gelatine
image is removed by water and a sponge, and the fatty image remaining
is treated in the usual way for lithographic printing.
.
I also form a printing surface upon stone or other surface in the
following manner, but I lay no claim thereto :-I spread a layer of
gelatine, alone or mixed with sugar or some other colloid, upon
smooth paper, which has previously received a thin smooth coating
of gum arabic and sugar, or gum arabic and glycerine. The gelatine
coating may be composed of gelatine, three parts; sugar, one part;
water, nine parts. If the paper or other surface so treated have to be
used at once one half part of the bichromate of potash in fine powder
may be added together with twenty drops of glacial acetic acid to each
imperial pint of the solution, the object of such addition being to cause
the gelatine to assume the insoluble condition without destroying its
:

page_text: sensibility and other properties, as is well understood. Or the paper
may be prepared without the addition of the bichromate and acid, and
may be made sensitive when required for use by immersing the paper in a
solution of the bichromate and acid, such solution being of the strength
of about five per cent. of the solid salts. When dry the sensitive paper,
prepared in either way, may be printed until the subject be seen fully
up, and must then be washed in very cold water until all the chrome
salts are removed. At this stage the gelatinous film will have left the
paper, if prepared as directed with a preliminary coating of gum, and
will have floated off. It may be reattached, the printed face being
upwards as directed for the application of the printed paper in known
methods, that is to say, by laying it out upon a porous lithographic
stone, and scraping out the water and air from between its surfaces. I
prefer, however, to mount it by the same means upon a flat plate of
zinc or copper which has been well grained, or upon a finely grained
or pumiced plate which has received a fine coating of india-rubber and
gum dammar, or of other resinous bodies of the like nature dissolved in
benzole, so as to retain the gelatine film upon the plate during the
operation of printing, as is well understood. The surface when so
applied is ready to receive the ink after being dried by means of blotting
boards. When in the state containing the proper amount of moisture
it will "ink up," as in Tessié de Motay's and other analogous processes.
By the use of prepared paper I can prepare these surfaces readily and
without any trouble in drying, and the surface so formed is printed
under a negative with greater ease than when upon a rigid support.
In witness whereof, I, the said Frederick Richard Window, have
hereunto set my hand and seal, this Sixteenth day of February,
in the year of our Lord One thousand eight hundred and seventy-
one.
Witness,
W. A. GILBEE,
4, South St.,
Finsbury.
FRED. R. WINDOW. (L.S.)