IMPROVEMENTS IN THE METHOD AND APPARATUS TO BE EMPLOYED. IN THE PREPARATION OF SURFACES FOR PRINTING OR ETCHING BY THE AID OF PHOTOGRAPHY
Year: 1884

page_text: [Communicated from abroad by Edward Kunkler, of St. Gall, in the Republic of
Switzerland, Civil Engineer, and Jacques Brunner, of Küssnacht, in the
Canton of Zurich, in the aforesaid Republic, Photographer and Art Printer.]
PROVISIONAL SPECIFICATION.
I ALFRED GEORGE BROOKES of No 55 Chancery Lane in the County of
Middlesex Fellow of the Institute of Patent Agents, do hereby declare the
nature of my invention for IMPROVEMENTS IN THE METHOD AND APPARATUS
TO BE EMPLOYED. IN THE PREPARATION OF SURFACES FOR PRINTING OR ETCHING
BY THE AID OF PHOTOGRAPHY to be as follows:-
The Invention relates to an improved process for the manufacture of Photographic
negative and positive plates hatched or grained of glass, paper card, board or any
other suitably transparent or translucent material adapted to the production of
types, cliches, or negatives, which can at once in a direct manner be used for the
production of highly and deeply etched devices on metals lithographic stone or
other suitable materials.
.
The methods or processes hitherto known and in use for the producing of cliches,
types, or negatives adapted for the etching on metals, stone, & generally require,
for the true rendering of the photographic images taken after Nature with their
middle tones, one or more intermediate manipulations between the photographic
negative and the ultimate surface in design to be transferred. These methods or
processes are therefore wanting in perfect nicety clearness or sharpness of contours,
shades and other details of the finished picture.
"
In operating according to this invention by which the grain or "hatching
required for the production of high and deep etchings is in most intimate contact
with the surface in design or negative or the picture itself and is, so to speak, most
intimately amalgamated or combined with it, and this process also offers the further
advantage, that the photographic plates, made for the above mentioned purposes
may be treated in the same manner as heretofore, which manner is well known to
every Photographer and Amateur, and used for the production of the ordinary
Photographic Negatives, so that only after the development of the photographic
image does the operation become a different one from that hitherto generally known
or practised and the designs or pictures obtained are adapted for direct transmission
onto the above-mentioned materials such as Metals, Stone, &c.

page_text: For the making of typographic or other like photographic plates (Negatives and
Positives) a transparent grained or hatched plate is employed and for its production
we preferably use bichromatized Gelatine.
A polished glass plate is covered on one side with "Chrom Gelatine," to which is
added more or less of "Chrom Kalium" (Bichromate of Potash) according as a
coarser or finer grain is wanted. After the drying of this prepared plate, at
a temperature of say 30° to 40° C. or 86° to 104° Fah. lower or higher according
to the grain required, the plate is freely exposed to light during some say 5 to 10
minutes more or less, according to circumstances and it is then well washed and
dried according to the manner usually practised in this Art.
After this the grained surface produced is inked with Printers ink or suitable
composition and then varnished with "Negative varnish." In producing hatched
typographic Positive or negative Plates we employ similar photographic matrices,
types, or cliches having thereon the desired hatchings or grainings.
For the production of typographic or such like dry-plates by this invention
variously denominated "Gelatine," "Collodion," "Emulsion," and "Pellicule," dry
plates, we expose them behind one or the other of the above mentioned, or other
transparent mother-plates, types, or matrices, in a copying frame" before a ground,
or semi-translucent roughened glass Plate to either natural, or artificial light and
then develop "fix" and wash the plate in any suitable known way. Then the
actinised film, or "layer," on the plate after undergoing suitable drying is well
"tanned"
or hardened" say by means of a concentrated solution of Alum and
then subjected to an Alcohol bath. The gelatinized plates are the covered over
with an isolating layer or film of collodion or "leather-collodion
"
or collodion
prepared with castor oil and then treated with an India-rubber, Albumen, or other
suitable isolating solution. The plate is then dried naturally or artificially and is
afterwards covered again with a layer of, or has applied to it, a sensitized solution,
Gelatine-Emulsion, or Collodion, and dried or allowed to dry.
After the
The plate is then ready for employment in the photographic art.
required exposure and subsequent "developing" and "fixing" the picture appears
on a beautiful "under-ground" presenting the predetermined quality of " graining'
or "hatching" adapted for the required end or purpose and it is thereby rendered
throughly adapted for direct high or deep etching (the emulsion, layer, proof, or
film, on the glass plate may be removed therefrom if so desired in manner similar
to that now employed sometimes for a like purpose with the ordinary dry plates.
Trade-Marks, firm-styles, or names and other desired words, cyphers, numbers or
other indications, either by means of a stamp, or in any other suitable manner may
be applied to the margins, or other parts of the plates so produced between the lat
and 2nd Emulsion film, or layers, which marks, words, numbers, cyphers, &c. then
appear after the exposure development, and "fixing" of the Cliche, type, or negative.
When the grained, or hatched negative, is desired to be produced of very large
size and with one sensitive layer for use in effecting the photomechanical transfer
of direct photographic takings onto large metal plates, cylinders, rolls, or drums,
for high, or deep, etching I find the following modification to be well adapted to
the purpose and to give excellent results.
A polished glass plate is covered with a very fine transparent, or diaphanous,
paper having upon it the "grain" or "hatching" produced by printing, or otherwise,
in such a manner that by cutting the said paper along the margins of the glass
plate such paper may ultimately be removed.
This paper stretched or distended on the glass plate is isolated by the application
of a suitable solution such for instance as raw collodion or Chrom-alum-Gelatine,
or India-rubber, and after the drying of the solution the paper is treated with a
sensitive solution of Collodion, or Gelatine-emulsion, in the usual well known way.
After the photographic exposure, the developement, the fixing, washing and
drying of the first diaphanous sensitive paper, sheet, or surface, a second, very pure
transparent, or diaphanous paper, is pressed onto the "finished" negative, so that
it adheres to that negative.
i

page_text: After properly drying. the whole combined preparation, forming now one sheet,
or leaf, is separated from the glass plate, or its equivalent supporting surface, by
cutting, or dividing it, around the edge, or margin.
The Negative," or "Positive," being covered on both sides by the transparent,
or diaphanous, paper, can be copied from either side, without sacrificing its
distinctness, or sharpness of details, whilst it is moreover protected from injurious
atmospheric influences.
Such a "Negative," or "Positive," sheet, or film, as has just been described will
be found extremely useful in and adapted to effect the repeated transfer of the
photographic picture by photo mechanical means onto the surfaces of large plates,
drums, rolls, cylinders or other forms of metal for the purpose of high or deep
etching being produced thereon for printing in colors, calico printing or other use."
If the purpose for which the sheet so prepared be that of printing in colors from
designs, or pictures, upon the surfaces of cylinders, or other forms, such sheet is
whilst still affixed on the glass plate carefully and evenly covered, or spread over,
with a thin isolating film of raw-collodion, and then with a thin solution of
Gelatine applied by means of a sponge, a broad flat brush, or other vehicle, adapted
to the purpose, and is then allowed to dry freely and throughly.
The Gelatine solution just referred to has been found well adapted to this purposé
when prepared by the admixture with the gelatine of one third part of alcohol and
two per centum of alum, but these proportions may be varied.
This Gelatine solution having been so applied then that portion of the design or
picture on the negative or sheet on which it is not desired that the color shall
appear, is covered or protected by the application of covering or blocking out ink
or material. This application of blocking out or covering material is effected
before the removal of the sheet from the glass plate or support.
After the covering or blocking out material has become properly dry, the sheet
or film is removed from the glass plate or equivalent support and is applied and
secured to the surface to which its application is desired such as to the surface of
a cylinder.
'
After the surface, such as that of a cylinder or drum, has been prepared for the
etching for the design for the first color desired, the prepared sheet or leaf may be
again used for the production of another similar design for the like surface of
another cylinder or form by stretching that prepared sheet or film onto a glass plate
or equivalent surface and securing it thereon whilst the covering or blocking out
material is being removed by sponging or otherwise with benzine turpentine or
other suitable solvent and then drying the sheet by means of blotting paper or
other suitable absorbent.
The design, or picture, is then again covered with covering color, or blocking out
material, in such a way that only the portions of the design desired for the next
color to be printed are left free or available for reproduction on the surface to be
printed from or etched. The subsequent treatment will then be like that already
described for the first color surface.
The like manipulations may then be similarly repeated for any further color
portions to be similarly represented by reserved portions of the design or picture
on the surface such as a printing cylinder, or drum, or other form.
The covering colour, or reserving, or blocking out matter should be so finely
ground or reduced and by admixture with benzine, or other suitable solvent,
brought to such a consistency, that its most useful powers of attenuation may be
secured.
In order to render such large surfaces of sheet so prepared of greater usefulness
it becomes necessary to afford means of securing them on the surface whereon the
design, or picture, is to be reproduced wholly, or in part and for this object the
following adaptation, or arrangement, of apparatus will be found useful.
The large negative, or positive sheet of transparent material produced as
described is wound round, or applied, to the cylindrical, or other contour, of the
surface desired to be etched, in design and such sheet having been so applied as

page_text: tightly and evenly and flatly as possible by the use of the means of retention
'hereafter detailed not only enables a better result to be attained but also permits
of its reuse for a large number of times.
The method of securing the sheets as aforesaid on the surface to which their
retention pro tempora is desired is as follows.
The cylinder, or other curved surface is formed hollow, which hollow cylindrical
form has pierced through it a number of radial holes of small size, reaching from
the periphery to the interior of the cylinder and supplemented if desired by two
other rows of small holes disposed in parallel lines, or other suitable disposition, or
the number of rows and their disposition may be varied and reaching across the
cylinder's surface from side to side that is to say in a direction parallel to its
axial line or otherwise suitably disposed. One or both of the axially supporting
parts of the rolls, or drums, may be formed, bollow, or so as to admit of an exhaust
being placed in communication with the interior of said cylinder, or drum, such as
a pipe from an air pump so as to create a partial vacuum, or reduction of pressure
therein.
One end of the transparent, or prepared sheet, or plate is then applied to the
cylindrical (surface, or drum, and the partial vacuum, or reduction of internal
pressure, being maintained by the exhaust and the drum, or cylinder, being caused
to revolve at a suitable speed, the prepared sheet or combined film is rolled, or
spread around the drum's surface and retained thereon. In order further to aid in
the better application of the prepared surface, or combined film, bearing the picture
or design destined for reproduction on the surface of the cylinder, a pressure
cylinder is employed driven by suitable gearing, or by frictional contact properly
timed and arranged to operate with gearing to that cylinder and like that cylinder
carried in suitable supports, or framing and bearings, et cetera, but which parts
need not be further described for the sake of simplicity and clearness: they forming
no essential part of the invention and being well understood by any competent
machinist. This pressure, or secondary cylinder, is most conveniently covered with
India rubber or other suitable elastic material adapted to afford an elastic pressure
to the sheet or combined film to be evenly spread by its agency around the surface
of the primary cylinder.
The operation of the exhaust within the primary cylinder is as follows. The
sheet of material described and carrying the picture being pressed or spread over
the holes pierced through the primary drum or cylinder, the exhaust within reduces
the internal pressure and the external air pressing on the external surface of the
sheet, such sheet becomes fixed, or retained, to the surface of the drum so long as
the partial vacuum be adequately maintained. This period will in most cases be
only so long as may be desirable for the application of the sheet and during the
exposure of the picture, or image, on the prepared sheet necessary for its
application to the drum, or cylinder's surface and so soon as the detaching, or
removal, of the prepared sheet be desired that may readily be effected by the
suspension of the exhaust when the internal pressure being restored the sheet will
be separable without its having suffered injury, or deterioration, thus permitting of
repeated reuse.
In referring to hatching or graining it is to be understood that by such term
being used no restruction is intended as to the character of pattern or effect which
is referred to as these will vary greatly with the nature of the design, or picture,
and such effects are variously denominated as hatching, cross-hatching, stippling,
graining mezzo-tinting, lining, sanding and other effects of a like nature.
Dated this twento ninth der of Ton 1924

page_text: I ALFRED GEORGE BROOKES of N° 55 Chancery Lane in the County of
Middlesex Fellow of the Institute of Patent Agents do hereby declare the nature
of my invention for IMPROVEMENTS IN THE METHOD AND APPARATUS TO BE
EMPLOYED IN THE PREPARATION OF SURFACES FOR PRINTING OR ETCHING BY THE
AID OF PHOTOGRAPHY and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
The Invention relates to an improved process for the manufacture of Photographic
negative and positive plates hatched or grained of glass, paper, or any other suitably
transparent or translucent material adapted to the production of types, cliches or
negatives which can at once in a direct manner be used for the production of
highly and deeply etched, devices on metals lithographic-stone, or other suitable
materials.
The methods or processes hitherto known and in use for the producing of cliches,
types, or negatives, adapted for the etching on metals, stone, &c generally, require,
for the true rendering of the photographic images taken after Nature with their
middle tones, one or more, intermediate manipulations between the photographic
negative and the ultimate surface in the design to be transferred.
These methods or processes are therefore wanting in perfect nicety clearness or
sharpness of contours shades and other details.
My invention consists first in a novel mode of producing the grain or "hatching”
(required for the production of high and deep etchings) and secondly in a mode of
producing this graining or hatching in the plate itself so that it is in intimate
contact with the surface design or negative, or the picture itself and is, so to speak,
amalgamated or combined with it and so that the photographic plates, made for
the above mentioned purposes may be treated in any of the well known methods
and used for the production of the ordinary Photographic Negatives.
For the production of typographic or other like photographic plates (Negatives
and Positives) a transparent grained or hatched plate is required and for its
production I preferably use bichromatized Gelatine.
A polished glass plate is covered on one side with "Chrom Gelatine," to which
is added more or less of "Chrom Kalium" (Bichromate of Potash) according as a
coarser or finer grain is wanted. The plate thus prepared is dried at a temperature
of say 30° to 70° C or 86° to 158° Fah lower or higher according to the grain
required whereby a very fine grained or stippled surface is produced in the film of
Chrom Gelatine. The plate is then freely exposed to light during some (say) 5 to
10 minutes more or less, according to circumstances and is then well washed and
dried in the usual manner. After this the grained surface produced is inked with
Printers ink or suitable composition and then varnished with." Negative varnish."
In producing hatched typographic positive or negative plates employ similar
photographic matrices types or cliches having thereon the desired hatchings or
grainings. As already indicated the degree of temperature varies with the
character of grain required and also somewhat with the quality of gelatine a little
practice will enable the operator to regulate the temperature.
The second part of my invention relates to the production of typographic or such
like dry-plates.
For this purpose I take "Gelatine' "Collodion "-" Emulsion "-" Pellicule" or
other similar dry plates and expose them behind a matrix plate having a grained

page_text: <<
or stippled surface prepared according to my invention or any other transparent
mother-plates types or matrices in a copying frame" before a ground or semi-
translucent roughened glass Plate to either natural or artificial light, and then
develop "fix" and wash the plate in any suitable known way. The exposed film,
or layer, on the plate after undergoing suitable drying, is well "tanned" or
"hardened" say by means of a concentrated solution of alum and then subjected to
an alcohol bath and covered over with a layer or film of collodion or "leather-
collodion," or collodion prepared with castor oil, and finally treated with an India-
rubber, albumen, or other suitable isolating solution.
The plate is then dried naturally or artificially and is afterwards covered again
with a layer of, or has applied to it, a sensitized solution Gelatine Emulsion, or
collodion, and dried or allowed to dry.
"
The plate is now ready for employment in the photographic art. After the
required exposure and subsequent "developing" and "fixing" the picture appears
on a beautiful grained or stippled ground presenting the predetermined quality of
graining" or "hatching" adapted for the picture and it is thereby rendered
particularly suitable for direct high or deep etching the emulsion layer, proof, or
film, on the glass plate may be removed therefrom if so desired in manner similar
to that now employed for a like purpose with the ordinary dry plates.
Trade marks firm-styles or names and other desired words cyphers numbers or
other indications either by means of impressions from an india-rubber stamp or in
any other suitable manner may be applied to the margins or other parts of the
plates so produced between the 1 and 2nd Emulsion films or layers, which marks
words numbers cyphers &c then appear after the exposure development and
'fixing" of the cliche type or negative.
<t
When the grained or hatched negative is desired to be produced of very large
size and with one sensitive layer for use in effecting the photomechanical transfer
of direct photographic takings onto large metal plates, cylinders, rolls or drums for
high or deep etching I find the following modification to be well adapted to the
purpose and to give excellent results.
"
"
A polished glass plate is covered with a very fine transparent or diaphanous
paper having upon it the " grain or hatching" produced by printing or
otherwise, in such a manner that by cutting the said paper along the margins of
the glass plate such paper may ultimately be removed.
This paper stretched or distended on the glass plate is isolated by the application
of a suitable solution such for instance as raw collodion or Chrom-alum-Gelatine,
or india-rubber and after the drying of the solution the paper is treated with a
sensitive solution of collodion, or Gelatine-Emulsion, in the usual well known way.
After photographic exposure, development, fixing, washing and drying, a second
very pure transparent or diaphanous paper is pressed onto the "finished" negative,
so that it adheres to that negative. The whole combined preparation, forming now
one sheet or leaf, is then properly dried and separated dividing it around the edge
or margin.
The Negative," or "Positive," being covered on both sides by the transparent
or diaphanous paper, can be copied from either side, without sacrificing its
distinctness or sharpness of details whilst it is moreover protected from injurious
atmospheric influences.
Such a "Negative" or "Positive" sheet or film as has just been described will
be found extremely useful in and adapted to effect the repeated transfer of the
photographic picture by photomechanical means to the surfaces of large plates,
drums, rolls, cylinders, or other forms of metal for the purpose of high or deep
etching being produced thereon for printing in colors, calico printing or other use. -
If the purpose for which the sheet so prepared be that of printing in colors from
designs or pictures upon the surfaces of cylinders or other forms such sheet is
whilst still affixed on the glass plate carefully and evenly covered or spread over
with a thin isolating film of raw collodion and then with a thin solution of gelatine

page_text: applied by means of a sponge a broad flat brush or other vehicle adapted to the
purpose, and is then allowed to dry freely and thoroughly.
The Gelatine solution just referred to has been found well adapted to this
purpose when prepared by the admixture with the gelatine of one third part of
alcohol and two per centum of alum but these proportions may be varied.
This Gelatine solution having been so applied then that portion of the design or
picture on the negative or sheet on which it is not desired that the colour shall
appear, is covered or protected by the application of covering or blocking out ink
or material. This application of blooking out or covering material is effected
before the removal of the sheet from the glass plate or support.
After the covering or blocking out material has become properly dry the sheet or
film is removed from the glass plate or equivalent support and is applied and
secured to the surface to which its application is desired such as to the surface of a
cylinder.
After the surface, such as that of a cylinder or drum, has been prepared for the
etching for the design for the first color desired, the prepared sheet or leaf may be
again used for the production of another similar design for the like surface of
another cylinder or form by stretching that prepared sheet or film onto a glass
plate or equivalent surface and securing it thereon whilst the covering or blocking
out material is being removed by sponging or otherwise with benzine, turpentine
or other suitable solvent, and then drying the sheet by means of blotting paper,
or other suitable absorbent.
The design or picture is then again covered with covering colour or blocking out
material in such a way that only the portions of the design desired for the next
color to be printed are left free or available for reproduction on the surface to be
printed from or etched. The subsequent treatment will then be like that already
described for the first color surface.
The like manipulations may then be similarly repeated for any further color
portions to be similarly represented by reserved portions of the design or picture
on the surface such as a printing cylinder or drum or other form.
The covering colour or reserving or blocking out matter should be so finely
ground or reduced and by admixture with benzine or other suitable solvent
brought to such a consistency, that its most useful powers of attenuation may be
secured.
In order to render such large surfaces of sheet so prepared of greater usefulness
it becomes necessary to afford means of securing them on the surface whereon the
design or picture is to be reproduced wholly or in part.
The large negative or positive sheet of transparent material produced as
described is wound round or applied to the cylindrical or other contour of the
surface desired to be etched in design and such sheet having been so applied as
tightly and evenly and flatly as possible by the use of suitable means of retention
not only enables a better result to be attained but also permits of its reuse for a
large number of times.
In referring to hatching or graining it is to be understood that by such term
being used no restriction is intended as to the character of pattern or effect which
is referred to as these will vary greatly with the nature of the design or picture
and such effects are variously denominated as hatching, cross hatching, stippling,
graining, mezzotinting, lining, sanding, and other effects of a like nature.
It is desired to be understood that no claim separately considered is made to the
well known process of making photographic dry plates or negative plates but that,
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declaro that what
I do claim is
1. The production of a grained or stippled surface upon a film or layer of Chrom
Gelatine or other similar substance substantially as and for the purposes firstly
hereinbefore described.

page_text: 2. The production of plates for photographic purposes wherein the sensitive film
is combined with a grained hatched or engraved surface substantially as and for
the purposes hereinbefore secondly described.