Improvements in or relating to Moulds or Matrices for Casting Stereo-plates.
Year: 1888

page_text: Date of Application, 31st Oct., 1888
Complete Specification Left, 18th July, 1889-Accepted, 24th Aug., 1889
PROVISIONAL SPECIFICATION.
Improvements in or relating to Moulds or Matrices for Casting
Stereo-plates.
I, JOHN BAKER of the Leys, Chipping Norton in the County of Oxford, Compositor,
do hereby declare the nature of this invention to be as follows:-
The surface of the typo forme for which tints are required is rolled over with
printers ink, and an impression of the forme taken upon a suitable sheet of paper, and
transferred to a prepared board having one side covered with an adhesive paste or
composition. The parts where the tints are required are then cut away.
The skeleton
thus formed is by inoistening its adhesive side, and applying a little pressure, then
fixed upon another prepared board. The whole then forms a mould or matrix where-
with a plate may be cast by the ordinary stereotyping apparatus.
For poster type, ornaments and borders the required pattern or design is transferred
to or drawn upon the prepared board of suitable thickness and the parts required are
cut away and proceeding as before described in the case of tint blocks a mould or
matrix is formed.
For a fancy ground a sheet of embossed paper, fancy book cover cloth or other
raised surface is mounted upon the board as before described.
For a fancy ground the portions of the mould may be prepared with embossed paper
fancy book cover cloth or other suitable material, or the device may be raised or
embedded or otherwise produced as for example by painting with a composition of
dextrine and starch, and thus any required device can be produced in relief as.
required, on a fancy ground or other part of the plate.
By this means chaos-type and seleno-type patterns can be produced in regular
designs or geometrical patterns.
I have had considerable difficulty in obtaining a suitable kind of board for these
moulds, but have at last produced a kind of board which I find does not curl contract
and will stand the heat of the metal by pasting together in layers wrapping paper
until the necessary thickness is reached."
Dated this 30th day of October 1888.
COMPLETE SPECIFICATION.
Improvements in or relating to Moulds or Matrices for Casting
Stereo-plates.
I JOHN BAKER of The Leys, Chipping Norton in the County of Oxford, Compositor,
do hereby declare the nature of this invention and in what manner the same is to he
performed, to be particularly described and ascertained in and by the following
statement :-
This Invention relates to the formation of moulds or matrices for casting stereo-
plates and consists first in the process of making paste board and of constructing the
moulds or matrices therefrom; secondly in the employment of a writing composition
by means of which such moulds or matrices may be embellished to produce either
intaglio or relief stereo-plates of predetermined or accidental design.
According to the first part of my invention I make paste board of the required
thickness (generally about one sixteenth of an inch) by pasting together a number of
sheets of smooth pliable and tough wrapping paper of any required size preferably of
a greyish colour.

page_text: In order that such boards may remain flat though subjected to the heat of the
molten metal I prepare the paste as follows:-
1 part by weight of good wheaten flour
1 part by weight of white starch
part by weight of powdered alum (as a preservative) mixed up smoothly with a
sufficient quantity of cold water for the purpose and boiled in the usual way for
making Bookbinder's paste adding when cool
part by weight of pulverised whiting
part by weight of glycerine
and mixing the whole intimately.
Having made the required paste board by pasting together sheets of suitable
wrapping paper with the composition paste hereinbefore described I put it in a
glazing press between polished iron or rolled zine plates and allow the composition
paste to become completely set under severe pressure.
The moulds or matrices are made from paste-board prepared in the manner
herein before described by uniting two boards; one the lower board providing the
surface to be stereo-typed; the other the upper board which is prepared one one with
a coating of dextrine-made ready for use by mixing with boiling water until it
assumes the required consistency-being perforated to expose the parts of the lower
board upon which the molten metal is to be poured, and to produce the outlines of the
design to be stereotyped.
The method of indicating the position in which the perforations in the upper board
are to be made will be understood by the following description of the operation for
producing a tint block or printing plate
A transfer of an impression of the type forme, for which a tint block or printing
plate is required, is taken upon the under or adhesive side of the upper board and the
parts where the tint is required are cut out by the aid of a knife, chisel or any other
suitable edged tool. The skeleton board thus formed is then moistened on its adhesive
sido and fastened to the lower board by the application of a moderate pressure until
the adhesive paste has taken firm hold of the lower board.
The reason for making a transfer impression on the adhesive side of the upper
board is to insure perfect fit to the key forme as this side determines the outline of the
face of the cast plate. A direct impression on the upper or non-adhesive side of the
upper board would indicate the position; but the knife or other cutting instrument
employed may swerve from a perpendicular cut and in that case the outline of the faco
of the tint block or printing plate would not be accurate; but if no key forme is
employed a direct impression upon, the top side of the upper board is preferable to a
transfer impression on the adhesive side.
In cases where the skeleton or upper board consists of detached portions, a gentlo
impression of the type and rule forme may be taken upon the surface of the lower
board to indicato the exact position in which such detached portions should be united
to the lower board.
If the tint block or printing plate is to show a fancy pattern, this may be obtained
by sticking embossed paper or cloth upon the lower board with the paste composition
hereinbefore described; or by embossing the surface of the lower board.
In such moulds or matrices plates may be cast by the ordinary stereotyping
apparatus or celluloid plates may be obtained by pressing sheets of celluloid into the
moulds as is done to obtain ordinary celluloid stereotypes.
;
According to the second part of my invention 1 employ a writing composition
consisting of
1 part by weight of dextrine
3 parts by weight of white starob

page_text: It may therefore be used for writing drawing or painting upon the surface of the
lower board at those parts which will be exposed by the perforation in the upper
board either the plain, or the embossed or fancy surface, hereinbefore described―so
as to produce intricate designs.
In the plate cast in such moulds or matrices the characters written drawn or
painted thereon will appear sunken. Ordinary pens may be used for writing with the
writing composition; but mathematical drawing pens are preferable when accurate
definition is required.
Quill pens may be used for thick work and a camel hair brush may be used for
painting wide lines or open spaces. In each particular case the writing composition
should be diluted according to the kind of pen used to such a degree as to make it flow
freely.
In the printing plate the sunken portions require depth in proportion to their width;
as in printing, the paper may be pressed a little into the crevices and so make a dirty
impression where no impression is required..
Greater depth is given to such wide sunken portions by the addition of a few drops
of stiff writing composition to the characters written drawn or painted upon the
mould.
In some cases the upper board need not necessarily be employed thus an intaglio
plate, that is, a plate having the ground in high relief and the characters sunken may
be obtained by writing drawing or painting the required characters with the writing
composition or tracing with the writing composition over characters first drawn or
printed upon the surface of the lower board of a mould, and then casting a plate.
;
Conversely a plate with the characters in relief may be obtained by printing
sketching or drawing the required characters upon a board with pencil or ink and
filling up
the whole surface of the board except the characters so printed, sketched, or
drawn thereon, with a layer of the composition and then casting a plate.
By the use of moulds constructed in the manner hereinbefore described and by the
employment of tho writing composition in the manner indicated, a variety of effects
may be produced.
Thus printing plates to produce effects similar to "chaostype" may be obtained by
cutting and preparing moulds to the required shape and casting the plates whilst the
moulds are in a somewhat damp state in a cold box, pouring the metal slowly but not
continuously.
Plates with "owltype' ""chaostype" or "selenotype" effects in definite patterns or
geometrical designs may be obtained by writing or drawing with the writing
composition such patterns or designs upon the lower board of a mould cut and prepared
to the right shape.
Plates to produce "Kaleidoscopic "effects may be obtained in the following
manner: Having cut and prepared a mould to the required sizo write or draw
upon the parts of the lower board, exposed through the perforation or perforations in
the upper board, any device or sprinkle some of the composition at random ;
after the composition has dried cast a plate; upon the same surface of the lower board
draw or write other devices in addition to those already drawn in the first instanco or
sprinkle a little more of the writing composition at random, when the additional
composition has dried cast a second plate; the same process can then be repeated for
a third plate. Such plates worked in the manner adopted with "selenotype" give
novel and effective decorative results.
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.
1. The manufacture of pasteboard from sheets of wrapping paper united by paste
composed of wheaten flour, white starch, pulverized whiting and glycerine with or
without the addition of powdered alum in the proportions approximately as specified
for the purpose set forth.

page_text: 2. The formation of moulds by uniting two boards in such a manner that the
perforations in the upper board may expose portions of the surface of the lower board
requiring to be stereotyped substantially as described.
3. In a mould formed by uniting two boards in such a manner that the perforations
in the upper board may expose portions of the surface of the lower board requiring to
be stereotyped, the preparation of such surfaces by embossing or by pasting thereon
embossed paper or book cover cloth, substantially as and for the purpose set forth.
4. In a mould formed by uniting two boards in such a manner that the perforations
in the upper board may expose portions of the surface of the lower board requiring to
be stereotyped the production of designs upon such plain or embossed or fancy surfaco
by characters written drawn or painted thereon with writing composition substantially
as described.
5. The production of intaglio or relief printing plates by writing drawing painting
or tracing upon a suitable surface with writing composition consisting of dextrine,
white starch and glycerine compounded in the proportions and in the manner
substantially as described and applied in the manner set forth.
Dated this 18th day of July 1889
AYRTON & THOMAS,
Agents for the Applicant.