Improvements in Transfer-Surfaces for Lithographic Purposes and the Process of Manufacturing the same.
Year: 1897

page_text: Date of Application, 31st Dec., 1897-Accepted, 12th Mar., 1898
COMPLETE SPECIFICATION.
Improvements in Transfer-Surfaces for Lithographic Purposes and
the Process of Manufacturing the same.
I, JOHANN ROTTACII, of Mariahilferstrasse, 61, Vienna, Austria, Xylographer, do
hereby declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:-
My invention relates to transfer-surfaces for lithographic purposes and to the
process of manufacturing the same, and has for its object to provide an efficient,
durable, and cheap transfer-surface which is light in weight and requires little
space when kept in store, and which may be repeatedly used for transferring the
drawing or other design produced on the same to lithographic stones.
According to my invention I produce transfer surfaces for lithographic purposes
as follows:-
I apply to a plane surface of metal, wood, leather, fabric, paper, or, as I prefer
cardboard of medium thickness, a coating or ground consisting of one thousand
parts by weight of water, one hundred parts by weight of gelatine, one to five
parts by weight of glycerine, and so much of zinc-white that the paste formed of
these ingredients may be still applied to the surface by means of rollers. I then
pour over such coating when dry a concentrated aqueous solution of alum. When
the whole has dried, if the coating is not insoluble in cold water, I again pour the
alum-solution over the coating, and then dry it; and I repeat this operation (if
necessary) until the coating has become insoluble in cold water, but usually one
or two treatments with alum-solution will be found sufficient. The transfer-
surface is then ready for use.
The proportions above given may vary considerably without affecting the result
to be obtained.
The drawing or design to be transferred is drawn or otherwise produced on the
transfer-surface obtained as above described with ordinary lithographic ink or
crayon (chalk) in any usual or suitable manner, and if desired the transfer-surface
is then coated with gum-solution for better preserving the drawing or design.
For transferring, the gum-coating is washed off and transfer-ink is then applied
to the transfer-surface in the usual way and after moistening such surface with
a weak gum-solution. After drying, the transfer-surface is placed on the stone
and the whole is passed through the press once or twice. The transfer-surface is
then taken off the stone, which can be done without any difficulty and without in
any way damaging the drawing or design on the transfer-surface or the latter itself.
The printing with the stone may then go on in the usual way and a fresh transfer
from the transfer-surface may be made as described, or the transfer-surface may
again be coated with gum-solution for keeping it in store for any desired length of
time.
In this way any desired number of transfers may be made from my improved
transfer-surface, so that instead of the heavy and expensive stones, the light and
inexpensive transfer-surfaces, which moreover occupy little space and may even
be wound up in rolls, may be kept in store for reprinting.

page_text: Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is:-
1. A process of manufacturing transfer-surfaces for lithographic purposes con-
sisting in applying to a plane surface of metal, wood, leather, fabric, paper, or
cardboard a coating of water, gelatine, glycerine, and zinc-white mixed to form a
paste, then alternately drying such coating and pouring over it a concentrated
aqueous solution of alum, and (if necessary) repeating these latter two operations
alternately until such coating has become insoluble in cold water.
2. As a new article of commerce, a transfer-surface for lithographic purposes
consisting of a backing of metal, wood, leather, fabric, paper, or cardboard and a
coating thereon substantially consisting of zinc-white, gelatine, and glycerine, such
backing having been rendered insoluble in cold water by alum.
Dated this 31st day of December 1897.
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.