IMPROVEMENTS IN THE MEANS OF PRINTING ON GLASS, PORCELAIN, FLOOR- CLOTH AND OTHER SURFACES, AND IN APPARATUS THEREFOR."
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by John James Emery at the Office of
the Commissioners of Patents on the 29th April 1880.
JOHN JAMES EMERY, of Lambeth, in the County of Surrey, Printer.
"IMPROVEMENTS IN THE MEANS OF PRINTING ON GLASS, PORCELAIN, FLOOR-
CLOTH AND OTHER SURFACES, AND IN APPARATUS THEREFOR."
My Invention is designed for the direct application by printing press to the
surface of glass, porcelain, earthenware, metal, wood, floorcloths, and other similar
rigid or irregular surfaces, of designs or lettering, whether coloured or otherwise,
by means of flexible negatives or blocks, thereby gaining an increased simplicity
aud economy over existing processes.
I form these flexible blocks of a composition, as hereinafter specified, which
while it retains a sharp and clear impression of the design is sufficiently plastic in
its nature to overcome the rigidity and inequalities of the surface of the substance
to be printed upon, and to be perfectly intimate in its contact when pressure is
applied by the two cushions fitted in the printing press.
The composition of which I form the blocks is as follows:-
9 lbs. of glue,
2 gallons of black treacle or molasses,
1
which are the essential ingredients,
2 ounces of Venice turpentine, which adds to rigidity and gives a holding surface
to the colour,
4 ounces of strong acetic acid, which prevents mould,
2/ pounds of india-rubber purified and dissolved in spirits of wine,
12 ounces of glycerine,
but these proportions may be slightly varied according to circumstances. Thus,
where the design presents bold lines, the glycerine and treacle may be reduced in
quantity, and where fine lines are needed they should be increased. When a block
is not required to be long preserved, or where its shrinking is unimportant, the
india-rubber and glycerine may be dispensed with, an equal bulk of glue being
substituted therefor.
I prepare the composition in the following manner: -
In an ordinary jacket pan or a vessel suspended in an outer one containing
water I boil the treacle for about twenty minutes, repeatedly skimming it, and
then add the solution of india-rubber and stir until thorough admixture has taken
place; I then add the glue, which must have been previously soaked in cold water
for about twelve hours, and drained of the superfluous moisture, and boil with
....

page_text: occasional stirring until the glue becomes incorporated with the mixture, which
usually takes place in about forty minutes; I then add the remaining ingredients,
and boil the whole for not longer than six or seven minutes, that is, just long
enough to thoroughly incorporate the mass without reducing it to a stringy nature.
It is now ready for use, and may be cast upon the moulds of the engraved surfaces
to be reproduced (such as " electros or sulphur moulds), a weight being placod
upon it as it begins to set.
"
The pressure necessary for the printing of the glass, &c., is applied by means of
an under and upper elastic cushion fitted to an ordinary printing press, which,
where the surface to be printed upon is curved or irregular, may with advantage
be water cushions.
The colour, when the flexible block is to print on glass, porcelain, metal, or other
surface where it has to be subsequently vitrified or enamelled, is mixed with a
medium composed of camphor and wax, in equal bulk dissolved in ether, and
mixed with fat, oil of turpentine, and oil of lavender, and, where a large mass of
colour is required, a little Venice turpentine. The firing is done in the ordinary
way. In other cases, or where it is not needed to vitrify or enamel, the ordinary
colours may be used.