AN IMPROVED PROCESS FOR OBTAINING PRINTING SURFACES
Year: 1863

page_text: LETTERS PATENT to Henry Rafter, of No. 5, Barrs Hill Terrace, Coventry,
in the County of Warwick, Artist, for the Invention of "AN IMPROVED
PROCESS FOR OBTAINING PRINTING SURFACES."
Sealed the 16th October 1863, and dated the 21st April 1863.
PROVISIONAL SPECIFICATION left by the said Henry Rafter at the
Office of the Commissioners of Patents, with his Petition, on the
21st April 1863.
I, HENRY RAFTER, of No. 5, Barrs Hill Terrace, Coventry, in the County of
Warwick, Artist, do hereby declare the nature of the said Invention for "AN
IMPROVED PROCESS FOR OBTAINING PRINTING SURFACES," to be as follows:-
This improved process is founded on the elasticity of india-rubber or similar
material, which in the following I will designate by the commercial name of
rubber. The elastic property of rubber I use in this process by taking a sheet
or plate of some porous or pervious substance, such as paper, unglazed
porcelain, or cloth, and drawing or writing on it, or transferring on it drawing,
writing, or printed matter by any of the usual transfer processes, using ink of
an adhesive quality or that which will adhere to the rubber. A sheet or film
of rubber is then pressed on the drawing or transfer, and allowed to adhere to
the part covered with the adhesive ink. The porous sheet or plato with the
rubber on it is then placed so as to form one of the sides or portion of an air-
tight compartment. The rubber side being placed outwards, air is then forced

page_text: into the compartment, which passing through the porous sheet or plate forces
outwards the rubber only, however, in those parts not adhering to the porous
sheet or plate. As long as the pressure of air is continued the rubber is found
projecting in convex surfaces from the sheet or plate, thus forming a mould which
being made conducting an electrotype can be taken which will be a surface fit
for printing from. Should the drawing, writing, or transfer be so made that
the adhesive ink forms the lines of the writing or drawing, the rubber will
project from those parts technically termed the "whites," and the electrotype
will bo suited for a typographic press, the lines being-in relief. Should the
drawing, writing, or transfer be so made that the adhesive ink forms what is
technically termed the "whites," the electrotype will be suited for a copper-
plate press, the lines being sunk. The drawing or transfer may be made on
the sheet or film of rubber instead of the porous sheet or plate. Instead of
air liquids or gases may be used. Instead of an electrotype the rubber at the
stage of the process previous to electrotyping may be backed by having melted
wax, gutta percha, glue, or some plastic material run over or pressed, and
made to adhere to the rubber, and then allowed to cool or harden. Then the
porous sheet or plate may be removed. The rubber will be found to form a
surface similar to the electrotype, and moulds and stereotypes may be
taken.
In the foregoing description of my Invention, when speaking of sheets or
plates I do not confine myself to the use of plain surfaces only, my Invention
being equally applicable to the production of curved or cylindrical surfaces,
and in the printing and impressing of textile fabrics with either relief or sunk
designs.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Rafter in the Great Seal Patent Office on the
20th October 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
RAFTER, of No. 5, Barrs Hill Terrace, Coventry, in the County of Warwick; s
Artist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of April, in the year of our Lord One
thousand eight hundred and sixty-three, in the twenty-sixth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Henry Rafter, Her special licence that I, the said Henry Rafter,

page_text: my executors, administrators, and assigns, or such others as I, the said Henry
Rafter, 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 Invention for "AN IMPROVED PROCESS
FOR OBTAINING PRINTING SURFACES," upon the condition (amongst others)
that I, the said Henry Rafter, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said In-
vention, and in what manner the same was to be performed, and causo
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 Henry Rafter, do hereby declare tho
nature of my said Invention, and in what manner the same is to be per-
formed, to bo particularly described and ascertained in and by the following
statement, that is to say :-.
My process for obtaining printing surfaces is founded on the elasticity of a
sheet or film of india-rubber or similar clastic gum or substance, which being
made in certain parts to adhere to a plate or sheet of a porous, permable, or
pervious and comparatively non-elastic material, or some non-elastic material
that is made permable or pervious in the parts not required to adhere.
A fluid is then made to pass through this non-elastic plate or sheet with a
certain degree of pressure, which expands the elastic sheet or film in those
parts not adhering. As long as the pressure is continued these parts are found
projecting in convex surfaces from the non-elastic plate or sheet, and the
surface of the elastic sheet or film in this state being made conducting with a
coat of plumbago, an electrotype can be taken, which will be the printing
surface required. The elastic sheet or film being made of india-rubber or
similar elastic gum or substance if required very thin, it is necessary to preparo
it by dissolving the india-rubber in some evaporating spirit such as benzine,
and spreading it on a sheet of paper which has been previously smeared with
a mucous substance, such as glue or starch, similar to the transfer paper used
in lithography, the mucous substance allowing the paper to be removed from
the india-rubber when the paper is damped. The non-elastic plate or sheet is
composed of any material possessing a smooth surface and a certain degree of
thinness, such as paper, porcelain, cloth, silk, metal, wood, leather, or parch-
ment. If the material is not naturally permable or pervious to fluids, it can
be made so by puncturing or piercing it in fine holes in those parts not required

page_text: to adhere. The fluid may be air, gas, water, or other liquid. The mode of
applying is by means of a box or compartment made of a substance not affected
by the electrotyping solution, and having one side or portion of such side open,
and the elastic sheet or film and the non-clastic plate or sheet so arranged as
to occupy this open place, the whole being made air-tight and waterproof.
The box or compartment to possess a valve admitting the fluid used, and the
fluid to be forced in to the requisite amount. To make the elastic sheet or
film and the non-elastic plate or sheet adhere, an ink in which rosin forms the
important part I find the most effective.
To simplify the description of the process in the following I use the india-
rubber prepared on the transfer paper for the "elastic sheet," porous paper for
the "non-elastic sheet," and "air" as the fluid.
To produce a printing surface with the lines of the drawing in relief for
printing from at the typographic press, the drawing is made either on the
elastic or on the non-elastic sheets, with an ink composed of the following
ingredients-soap, 5 ounces; rosin, 5 ounces; drying oil, 5 ounces; lamp
black 3 ounces. These being incorporated by means of heat, the ink produced
is cast into cakes similar to lithographic ink, and used in the same way by
dissolving it in soft water. The drawing may be made with lithographic chalk
and then dusted over with finely ground rosin, which adheres only to the chalk,
and is easily removed from the rest of the surface by gently blowing off the
superfluous particles. This mode of using the rosin generally used will greatly
increase the adhesion. The two sheets, with the drawing inwards, are then
pressed together by means of a screw press on a metal plate, heated sufficiently
to melt the rosin, which causes the sheets to adhere at the lines of the drawing.
The transfer paper is then damped and removed; the two sheets, with the
elastic sheet outwards, are then placed so as to form a side or portion of the
air tight box or compartment, with the valve admitting air. Air is then forced
into the box or compartment, which passing through the non-elastic sheet
expands the elastic sheet in those parts not adhering; these form the parts
technically known as the "whites" of the drawing, a mould for an electrotype
being thus formed. The electrotype will have the lines of the drawing in
relief. The two sheets may be placed so as to form the side or portion of the
air-tight box or compartment, with the elastic sheet inwards. The air can be
drawn out of the box or compartment, thereby forming a vacuum. The air
outside will penetrate the non-elastic sheet, and expand the elastic sheet.
A coat of varnish composed of a solution of ten ounces of gum lac in a pint of
spirits of wine is then spread over the exposed surface of the non-elastic
sheet; when dry the sheets are removed from the box or compartment, and

page_text: the parts of the elastic sheet where not adhering will be found projecting, the
air being confined by means of the varnish.
For a drawing with sunk lines for printing from at the copper-plate press,
the drawing is made with an ink composed of common writing ink, in which
is dissolved some treacle or sugar; the drawing is then covered with an ink
composed of thin lithographic varnish, which is incorporated with one-fifth its
weight of rosin; a stream of warm water is then poured over, which dissolves
the treacle ink, and leaves the varnish and rosin ink in those parts technically
known as the "whites" of the drawing; I then, as in the preceding, obtain
the electrotype, but with sunk lines.
For the reproduction of an existing engraving on metal, on wood, or a
lithographic subject, when access can be had to the original plate, block, or
stone, I take an impression of the same on either the elastic, or on the non-
elastic sheets, in the ink usually used, provided that the said ink is first incor-
porated by means of heat with one-fifth its weight of rosin, and that finely
ground rosin is dusted over the impression, then proceeding as above to obtain
the electrotype. When access cannot be had to the original plate, block, or
stone, I take an ordinary impression on paper, which submitting to moderate
heat, I sponge over it a weak solution of gum water, and rolling it with the
lithographic ink incorporated with one-fifth its weight of rosin. I then wash
away the
gum and dust, rosin over the impression, and proceed as above to
obtain the electrotype. Should the paper on which this impression is printed
not be permable or pervious, it must be made so by puncturing it with a fine
needle point in the "whites" of the engraving.
I can also reproduce a drawing or engraving by photographic process by
means of light passing through the transparency of the paper. Or else I take
a photographic negative, or a photographic proof of the said drawing or
engraving, and applying this negative or proof over either the elastic or the
non-elastic sheets, over the surface of which I previously spread a layer of
bichromate of potash, dissolved in gelatine, as stated by Talbot, the whole
being exposed to the action of light during a longer or shorter time, then
passing over the gelatine a layer of ink composed of lithographic varnish
incorporated with rosin. By means of water, I wash away the gelatine where
not acted on by the light. The varnish and rosin ink remains only on the
gelatine left, and the impression produced is ready for the remaining process
to obtain the electrotype. Or else by using bitumen of Judea dissolved in
benzine, spread however in this case only on the non-elastic sheet, then
applying the negative and dissolving the bitumen of Judea where not acted
on by the light. I sponge the sheet with weak gum water, and roll it with

page_text: lithographic varnish incorporated with rosin, washing away the gum, the sheet
will be in the required condition to proceed to obtain the electrotype.
In the foregoing description of my Invention, when speaking of plates and
sheets, I do not confine myself to the use of plane surfaces only. It is obvious
that with modifications my Invention is equally applicable to the production of
curved or cylindrical surfaces; nor do I confine the Invention for producing
printing surfaces for use only at the presses named, but also for impressing,
printing, and imbossing of textile and other fabrics with either relief or sunk
designs.
Whatever may be the modifications which experience and practice may
show to be desirable, I claim as my Invention the action of a fluid by pressure
passing through a porous, permable, or pervious material, and expanding in
certain parts, an elastic sheet as related above, claiming the exclusive right
thereto, and its application for the purpose of obtaining printing surfaces, and
I take advantage of the action of some substances on each other for producing
some effects for obtaining the above results.
In witness whereof, I, the said Henry Rafter, have hereunto set my
hand and seal, this Nineteenth day of October, in the year of our
Lord One thousand eight hundred and sixty-three.
HENRY RAFTER. (L.s.)
Signed and sealed in the presence of
W. B. SANDERSON,
Actuary to the Warwickshire Savings Bank,
Northgate Street,
Warwick.