AN IMPROVED IMPLEMENT FOR STIPPLING ON LITHOGRAPHIC STONES OR PLATES, AND FOR SIMILAR PURPOSES
Year: 1881

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for an Invention of
"AN IMPROVED IMPLEMENT FOR STIPPLING ON LITHOGRAPHIC STONES OR
PLATES, AND FOR SIMILAR PURPOSES." A communication from abroad by
John Gast, of Brooklyn, New York, United States of America.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at
the Office of the Commissioners of Patents on the 7th June 1881.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "AN IMPROVED IMPLEMENT FOR STIPPLING
ON LITHOGRAPHIC STONES OR PLATES, AND FOR SIMILAR PURPOSES." [A communi-
cation from abroad by John Gast, of Brooklyn, New York, United States of
America.]
This Invention relates to an improved pad or device for stippling on lithographic
stones, zinc, or metal plates, and for other uses in the art of lithography and
printing.
"
The object of the said Invention is to produce a pad or device whereby stipple
work may be rapidly and artistically accomplished, and which will be of such
elasticity that it will yield sufficiently to pressure, and which will be of the
necessary durability, and neither shrink, break, crack, nor become soft when
subjected to ordinary atmospheric changes.
The following is a formula of the ingredients constituting the preferred
composition of which the said pad or device is made, viz:-
Ten (10) pounds of india-rubber, twelve (12) ounces of sulphur, forty eight
(48) ounces of vermillion, twenty (20) ounces of French zinc-white, four (4) ounces
of powdered soapstone. These ingredients are thoroughly mixed together, gentle
beat being applied to render the mass homogeneous. While a compound consisting
of the above named ingredients is preferred for the formation of the said pad or
device, it is obvious that they may be varied some what without departing from
Paine 1

page_text: the principle of the said Invention. For instance, in lieu of employing vermillion,
which gives the compound a reddish color, I may use an analogous material. If a
yellow color is to be produced, I employ chromo-yellow and cadmium; if a green
color, I use chrome-yellow or lemon-yellow and Antwerp blue, Prussian, Milori,
or any other blue; for a blue color I prefer to use chrome-green and ultramarine
or cobalt.
It will be desirable however to employ a color of about the same relative weight
and bulk as vermillion to attain the proper degree of elasticity. If the color used
is much lighter in weight than vermillion, its proportion of weight should be
made up with the zinc-white or its equivalent. The compound is now in one
homogeneous mass, and my object is to reduce it to small pieces or pads of proper
size and thickness, one side of the same being smooth and the other side having a
stippled or grained surface in relief, the piece or pad being also vulcanized."
The process of treating the compound to form the pads described will be as
follows:-
I first draw or stipple on stone with a pen the style and size of grain of stipple-
work to be produced in relief on the surface of the said pad or device; the size and
style of grain may be varied at will. From the stone a print of the stipple-work
is taken on white paper, from which relief-plates are made by the photo-engraving
process, or by any other suitable method. I next take plaster casts or negative
metal casts from the relief-plates, and from these plaster or metal casts the india-
rubber pads receive the impression of the stipple work. The pads having been thus
formed are then vulcanized according to the following method:-
The india-rubber compound is rolled into a thin sheet of, say, about one-eighth
of an inch in thickness, and then cut into smaller pieces or pads of proper size to
fit the plaster negatives (or plaster moulds) upon which they are placed and pressed
firmly down by a smooth polished metallic plate applied to the back of the india-
rubber, whereby the said back is given a smooth surface.
As a precaution, prior to placing the metal plate upon the india-rubber, I prefer
to first powder the back of the pad with fine soap-stone dust, and then spread a
smooth sheet of tin-foil over it, afterwards placing the polished metal plate upon
the tin-foil. This is done to prevent the metal from blackening the back of tho
pad during the vulcanization of the latter. The metal plate is screwed tightly to
the plaster mould by means of a pair of clamp-irons of usual construction. In
order to prevent the plaster mould from breaking during this operation, it may be
formed within an iron-chase of proper size. The plaster mould with the india-
rubber held upon its surface by the polished metal plate and clamp-irons is then
introduced into a steam vulcanizer and submitted to a heat of about 265° Fahrenheit
for a space of about from 4 to 5 hours. I recommend that great care bo exercised
in this step of the process, since the proper vulcanization adds greatly in giving
the pad the required toughness and elasticity, so as to be just suitable and
applicable to transfer an impression by the touch of the finger, hand, or stylus.
After the vulcanization the pads are taken out and are ready for use, one side being
smooth and the other bearing the impression of stipple-work taken from the
plaster mould.
The device above described, in lieu of being a flat printing pad, may be mounted
upon a roller, or otherwise, as may be preferred.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Lake in the Great Seal Patent Office on the
5th December 1881.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "AN IMPROVED IMPLEMENT FOR STIPPLING
ON LITHOGRAPHIC STONES OR PLATES, AND FOR SIMILAR PURPOSES." A communi-
cation from abroad by John Gast, of Brooklyn, New York, United States of
America.
This Invention relates to an improved pad or device for stippling on lithographic
stones, zinc, or metal plates, and for other uses in the art of lithography and
printing.
The object of the said Invention is to produce a pad or device whereby stipple
work may be rapidly and artistically accomplished, and which will be of such
elasticity that it will yield sufficiently to pressure, will be of the necessary
durability, and will neither shrink, break, crack, nor become soft when subjected
to ordinary atmospheric changes. I term my improved pad or device a
stigmograph."
The following is a formula of the ingredients constituting the preforred
composition from which the said pad or device is inade, viz:-
Ten (10) pounds of india-rubber, twelve (12) ounces of sulphur, forty-eight
(48) ounces of vermillion, twenty (20) ouuces of French zinc-white, four (4) ounces of
powdered soapstone. These ingredients are thoroughly mixed together, gentle heat
being applied to render the mass homogeneous. While a compound consisting of
the above-named ingredients is preferred for the formation of the said pad or device,
it is obvious that they may be varied somewhat without departing from the principle
of the said Invention. For instance, in lieu of employing vermillion, which gives the
compound a reddish color, I may use an analogous material. If a yellow color is
to be produced, I employ chrome-yellow and cadmium; if a green color, I use
chrome-yellow, or lemon-yellow and Antwerp blue, Prussian, Milori, or any other
blue; for a blue color I prefer to use chrome-green and ultramarine or cobalt. It
will be desirable however to employ a color of about the same relative weight and
bulk as vermillion, to attain the proper degree of elasticity. If the color used is
much lighter in weight than vermillion, its proportion of weight should be made
up with the zinc-white or its equivalent.
The compound is now in one homogeneous mass, and my object is to reduce it to
small pieces or pads of suitable size and thickness, one side of the same being
smooth and the other side having a stippled or grained surface in relief, the pieces
or pads are also vulcanised.
The process of treating the compound to form the pads described will be as
follows, that is to say:-I first draw or stipple on stone with a pen the style and
size of grain of stipple-work to be produced in relief on the surface of the said pad
or device; the size and style of grain may be varied at will. From the stone a
print of the stipple-work is taken on white paper, from which relief-plates are
made by the photo-engraving process, or by any other suitable method. I next
take plaster casts or negative metal casts from the relief-plates, and from these
plaster or metal casts the india-rubber pads receive the impression of the stipple-
work.
The pads having been thus formed are then vulcanized according to the
following method, that is to say-The india-rubber compound is rolled into a thin
sheet of, say, about one-eighth of an inch in thickness, and then cut into smaller
pieces or pads of proper size to fit the plaster-negatives (or plaster moulds) upon

page_text: which they are placed and pressed firmly down by a smooth polished metallic plato
applied to the back of the india-rubber, whereby the said back is given a smooth
surface. As a precaution, prior to placing the metal plate upon the india-rubber,
I prefer to first powder the back of the pad with fine soap-stone dust, and then
spread a smooth sheet of tin-foil over it, afterwards placing the polished metal
plate upon the tin-foil. This is done to prevent the metal from blackening the
back of the pad during the vulcanization of the latter. The metal plate is screwed
tightly to the plaster mould by means of a pair of clamp-irons of the usual
construction. In order to prevent the plaster mould from breaking during this
operation, it may be formed within an iron chase of proper size. The plaster mould
with the india-rubber held upon its surface by the polished metal plate and clamp-
irons is then introduced into a steam-vulcanizer and submitted to a heat of about
265° Fahrenheit, for about from 4 to 5 hours. I recommend that great care be
exercised in this step of the process, since the proper vulcanization adds greatly in
giving the pad the proper toughness and elasticity, so as to be just suitable and
applicable to transfer an impression by the touch of the finger, hand, or stylus.
After the vulcanization the pads are taken out and are ready for use, one side
being smooth, and the other bearing the impression of stipple-work taken from the
plaster-mould.
The foregoing is an accurate description of my improved pad for stippling, and
the mode of its manufacture. In using it for stippling on stone, the following
steps should be taken, that is to say:-The outlines of the design having been
drawn, the solids filled in, and the sharp lines gummed out in the usual way, the
stippling pad which has received a coating of lithographic transfer ink from a
common printers' roller, or otherwise, is laid over the stone where wanted. If an
even tint is desired, the instrument is pressed gently and evenly with the hand, or
otherwise, and if a darker tint or thicker dots are required, the pressure is
increased.
If it is not desired to gum out the lights on the stone, they may be scraped out,
like those on what are known as "rub-tints" or asphalt drawings, and beautiful
soft effects produced.
"
The device above described, in lieu of being a flat printing, pad, may be mounted
upon a roller, or otherwise, as may be preferred.
Having thus fully described the said Invention, as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,
The implement or device, hereinbefore described, constructed substantially as
above set forth and for the purposes specified.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Fifth day of December, in the year of our Lord One
thousand eight hundred and eighty one.