New or Improved Plates for Printing..
Year: 1894

page_text: Date of Application, 27th Sept., 1894-Accepted, 29th Dec., 1894
New or Improved Plates for Printing..
I, GEORGE ISAAC, of 87 Leibnitz Strasse, Charlottenburg, in the Empire of
Germany, Newspaper Publisher 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:-
This invention relates to improvements in printing plates for books, pictures,
newspapers and other like printing in which high printing plates are employed.
These plates have heretofore possessed several disadvantages especially as regards
the time and cost of production, and that the printing obtained from them, especially
works of art, often leaves much to be desired. Woodcuts, as is well known,
especially when they are required to be good, not only cost a great deal of time
and money to produce but do not permit of a true and natural rendering of the
object or person to be reproduced. Zino and copper etching is also a too costly
and tedions means of production. By means of the autotype process true photo-
graphic prints can be obtained in less time than by woodcuts, but on the one hand
autotype printing for daily papers requires too much time, and on the other hand
autotypes cannot be stereotyped as is absolutely necessary in modern newspaper
printing, whereby a third inconvenience arises, namely, that for autotype printing
a fine glazed paper must be used, and such paper cannot be employed in an
ordinary daily newspaper. Numerous experiments have also been made with
gelatine reliefs, but no satisfactory results have been obtained, because the gelatine-
reliefs cannot be reproduced either by storeotyping, or by the galvano-plastic process.
The object of the present invention is to remedy the above mentioned defects, and
it aims at the production of high-printing plates of all kinds. The process not only
yields beautiful artistic prints, but yields them in a short time, so that the newspaper
reporter is in a position to illustrate clearly and accurately his report of actual
events, or to publish important personal portraits by means of photographs taken
on the spot. The process consists as follows:-
A gelatine relief is first obtained from the object to be represented, by means of
photography in any suitable way, or any other suitable relief may be employed.
A thin pulp is then prepared which contains one or more substances which harden
into a stiff compact mass, such as, for example, lime, plaster of Paris, magnesia,
cement, putty, and so forth. If, when these substances come in contact with a
liquid, they harden too quickly, it is preferable to mix them with some substance
which retards the setting or hardening, and imparts to the mass a considerable
amount of hardness and toughness. By this means sufficient time is allowed for the
thin pulp to fill the finest parts of the gelatine relief whilst a sufficient firmness and
tenacity is given to the hardened mass to enable the plates produced from it to be
used for printing in the same manner as wood or metal. Suitable materials for this
purpose are glue, dextrine, gum arabic, starch, soluble glass, white cheese, or any
suitable material containing gelatino or starch.
The proportions of the various substances employed may be varied according to
circumstances, but I have obtained good results by first making a solution consisting
either of one part of glue to twelve parts of water, one part of dextrine to six parts
of water, one part of gum arabic to twelve parts of water, one part of starch to
three parts of water, one part of soluble glass to fifty parts of water, or one part of
what is known in Germany as "weisse küse" or white cheese to three parts of
water, and then adding to and thoroughly mixing with each 100 grammes

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of any one of these solutions or of a mixture of two or more such solutions either
250 grammes of lime or cement, 230 grammes of plaster of Paris, or 120 grammes
of putty. When magnesia is used it may be mixed with a sufficient quantity of a
solution of chloride of magnesium of 30 Beaumé strength to produce a pulp of the
required consistency.
The pulp thus prepared of the required consistency is now poured on to the
gelatine or other relief, which is provided with a lip or rim, until it attains a
thickness of several centimetres. When the pulp has set, the lip or rim is removed
from the relief and the plate is lifted off, the latter is further hardened and then
only requires to be levelled at the back to render it fit for immediate use as a
printing plate.
Having now particularly described and ascertained the nature of the said invon-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
.
First. The employment of hardened and toughened lime, plaster of Paris,
magnesia, cement, and other such like substances in the process of printing,
substantially as described.
Second. The production of printing plates for printing books, newspapers, paper-
hangings and the like by casting a pulp composed of lime, plaster of Paris, magnesia,
oement or other similar substance capable of becoming stiff or hard, on gelatine,
wood, metal, or other relief, substantially as described.
Third. In the process forming the subject of the second olaiming clauses hereof
the addition to the lime or other. similar pulp, of gelatinous, starchy, or other
substances for the purpose of retarding the setting or hardening of auch pulp and
for increasing the firmness and tenacity of the lime or other similar plate,
substantially as described.
Dandahin 7th ISL 1004