IMPROVEMENTS IN THE PRODUCTION OR PREPARATION OF PRINTING SURFACES
Year: 1856

page_text: PROVISIONAL SPECIFICATION left by John Hamilton Glassford at the
Office of the Commissioners of Patents, with his Petition, on the 3rd
April 1856.
I, JOHN HAMILTON GLASSFORD, of Glasgow, in the County of Lanark,
North Britain, Lithographer, do hereby declare the nature of the said
Invention for IMPROVEMENTS IN THE PRODUCTION OR PREPARATION OF PRINTING
SURFACES," to be as follows, that is to say:-
This Invention relates to the production or preparation of printing surfaces
the application of electrotype processes to engraved or etched surfaces of
stone, zinc, or metal, so as to produce cylindrical plate and block-printing
surfaces, suitable for the purposes of the calico printer, and suitable for
printing textile fabrics, paper hangings, and other materials of various
kinds.
In proceeding to produce printing surfaces, according to this Invention,
from the surface of an ordinary lithographic stone or piece of metal of a
flat form, which has either an intaglio or a raised or relievo design made
thereon by etching, engraving, or otherwise, as described in the Specification
filed by me under Letters Patent obtained by me on or about the Fifth day of
September, One thousand eight hundred and fifty-five, or in any other mode.

page_text: I first prepare the surface of the stone, zinc, or metal, whether the design be
intaglio or relievo, by applying thereto a metallic conducting coating, such as
is used in the electrotype process, and when so treated, I then place the stone,
zinc, or metal in an electro-deposition trough or chamber, so that the prepared
surface of the stone shall be electrotyped in the usual manner, or in any
modified manner which may be found convenient for obtaining a copper or
other metallic coating.
design I
The metallic coating or electro plate thus formed upon the prepared surface
may be of any desired thickness, and when removed from the surface of the
stone or metal upon which it has been deposited it will have an intaglio or
relievo design or figure thereon, as the case may be, which may be used for
printing from, according to the ordinary mode of block or press printing, or
according to the mode usually adopted by calico printers in flat printing.
Where more than one color is required by the printer to complete a
produce the several desired colors by using a separate electro plate for each, as
follows, that is to say, I take what is known in lithographic printing as a
"sett-off" from the stone or piece of metal, on which only that part of the
design intended for the first color has been produced and transferred to all the
flat stones or pieces of metal intended to be used; I then paint on each respec-
tively the other portion of the design applicable to a different color in the
usual way; and thereafter having the portions so painted brought up, pro-
ceed to etch, so as to produce an intaglio or relievo surface, as required on
each stone or piece of metal representing the color which is wanted to fit
with the others and make up the whole design. By the successive use of the
electro plates obtained from these several stones or pieces of metal in the
manner already described the printing of the whole design is accomplished in
the usual way.
I
In order to adopt the metallic or electro-plate coating thus obtained to
cylinder printing when that is required, I bend and fix it round a roller of
iron or other suitable material of the diameter of rollers used in printing; and
I unite the edges by galvanic soldering or other well-known means; the iron
or other roller is then mounted on a spindle or axle, and used: in the way
common amongst cylinder printers.
But instead of printing directly from an electro plate obtained immediately
from an engraved or etched stone or plate, an electro plate, made as herein-
before described, may be used for the purpose of obtaining a second or electro-
printing plate therefrom, by the application of the electrotype process thereto
in like manner, as herein-before described, in which case the second or electro-
printing plate thus obtained will have printing surfaces precisely the same as

page_text: the original stone or plate, whereas the figures upon the electro plate obtained
directly from the surface of the original stone or plate will have inverted
figures thereon.
I I may observe, that in order to protect the surface of a lithographic stone
when intended to be used directly for printing, whether in a flat or cylindrical
form, I can do so by depositing and leaving upon it the metallic coating
obtained in the manner herein-before mentioned, but which coating must be
so thin as not to injure the sharp edges of the design on the side to be printed
from.