Improvements in the Method of Treating and Preparing Lithographic Stones for Printing.
Year: 1890

page_text: Date of Application, 10th Oct., 1890-Accepted, 14th Mar., 1891
Improvements in the Method of Treating and Preparing
Lithographic Stones for Printing.
I, LOUIS BENOIT, of Barmen, Germany, Lithographer, 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 :—
The methods that have been in use until now for producing reproductions of
prints and drawings in the lithographic manner consist in that, that the letters,
pictures or lines are brought upon the stone, which had before been newly polished
or pumicated, by the use of ink rich in fatty or greasy and resinous matters, or else
one uses ordinary printers or lithographers ink and transfers the letters upon the
stone and adds the necessary fatty parts in a fluid state afterwards.
It is an essential condition with this manner of working that the stone be finely
punicated as otherwise the drawings or letters would not stick to the stone and
could not be reproduced exactly and they are easily spoiled.
The old manner of proceding requires a great many manipulations and
operations taking much time and causing a great deal of trouble for preparing a
stone.
By the method invented by me many of these operations are avoided, but
the principal advantage of it is that a stone can be restored and made fit for other
objects without requiring to be pumicated and therefore a stone will last much
longer.
My method consists in the following:
I make the stone sensible for the slightest fat by treating it with alum, then I
fix the drawing upon it and withdraw the transfer paper very cautiously, then
I gun the stone well and let it dry; after that the gum washed off and immediately
after this ordinary lithographers ink is rolled over it and now it is powdered with
rosin and then it is etched and gummed anew when the stone is ready for use.
A so prepared stone, having served its purpose, which then shall be used again
for a new drawing is washed with turpentine and any fat which may have been left
is destroyed by the use of acid and thus the stone is made sensible again for new
fat and is ready for a new drawing without the old one having been destroyed by
punicating.
Ten to twenty minutes are sufficient to restore a stone of any size, whereas with
the old manner of working the pumicating alone took up to five hours with large
stones.
This however is not the only and not the principal advantage of my method;
the same allows, without difficulty, to lay a second design, for instance hatchings or
other designs, over the first because the stone has been made sensible for a second
drawing without injuring the first in the least and with absolute security.
Therefore one is enabled to lay two and more drawings one above the other and
to reproduce the same in one proof.
In consequence of the peculiar manner of preparing the stone the same receives
a surface not like polished but somewhat granulous, retaining the finest line or dot
and reproducing it equally fine.
A shortened and simplified method has been invented formerly, but one of its
principal conditions is that the stone must be pumicated, after one design has been
printed from it, and if it shall then be made fit for a second design. It is not
possible to print two designs in one operation or at any rate with uncertainty only
and by taking the most extraordinary care of the first design and by avoiding every
other operation with the stone.

page_text: In putting the three methods together and comparing them their differences will
be best observed and understood.
pumicating the stone.
transfering with fat
ink.
gumming and drying.
washing off the gum.
treating with gum
water.
rolling in the fat ink.
drying.
1) pumicating the stone.
2) transfering with ordin-
ary ink.
3) gumming and drying.
4) washing off the gun.
5) treating the stone with
a solution of asphalt
wax and rosin in tur-
pentine.
1) treating the stone with
acid & alum.
2) transfering with ordin-
ary ink.
3) gumming and drying.
4) washing off the gum.
5) rolling in ordinary ink.
6) powdering with rosin.
etching
This shows that the two old methods start with pumicating the stones, an
operation absolutely excluded from my method; it is therefore not possible in the
two first cases to transfer two or more drawings one upon the other and to
reproduce the same in one proof.
After a certain design, say for instance on a label or etiquette or on a sign board,
has been drawn on the stone and printed, giving its main characteristic features on
an open ground, it is found desirable, for some reason or other, to print the same
characteristic features again, but for the sake of distinction from the first, with all
or part of the spaces left blank before or not entirely black, having now a ground
of some sort laid or drawn in or over it, it will not be necessary, if one proceeds
according to my method to make or prepare a new stone; the ground can be laid
in the stone in use and copies can be taken reproducing both, the original and the
second design. In the same way a third design may be laid upon the same stone
and reproduced with the two first ones.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, 1 declare that what I
claim is :-
"The method of transfering one or more drawings upon stone without the use
of transfering ink and to reproduce the same in one proof consisting in that, that
the stone having once been made even and smooth is made sensible for treating it
with acid and alum, thus making it possible to transfer several drawings one upon
the other with certainty and reproduce them in one proof."
Dated this First day of March 1891.
KARL I. MAYER,
Agent for L. Benoit.