FACILITATING THE USE OF PRINTING PLATES OR ROLLERS IN METALLOGRAPHY
Year: 1885

page_text: Metallography.
I, MAX JAFFÉ of Vienna, in the Empire of Austria, Lithographic Printer,
do hereby declare the nature of my invention for: "FACILITATING THE USE OF
PRINTING PLATES OR ROLLERS IN METALLOGRAPHY" to be as follows:-
This invention relates to metallography.
When printing in the usual manner from plates or rollers made of zine or other
metals, it often happens that the ink adheres to portions of the plate or roller
which ought to remain uncoloured, while, the outlines of the figures turn out rough
or uneven.
According to this invention, these drawbacks are obviated by wetting the metal
plates or rollers, every time before they are inked for printing a copy, with a highly
diluted aqueous solution of either an acid or an alkali, to which a small quantity
of an amylaceous substance, or of glycerine, or of sugar or syrup is added instead
of with water as heretofore.
The acid or alkali slightly roughens the surfaces not covered with lithographic
ink and thereby enables them to hold the liquid better.
The acid or alkali may be replaced by salts, or oxides capable of exerting a
corroding influence on the metal plate or roller.
An advantage of this invention is that the plate or roller, after having the
drawing or design transferred to the same, is etched by moistening its whole.
surface with a diluted acid or alkali, and washing the same with pure water after
drying; this etching may be carried so far as to produce a high-relief.
Dated this 9th day of Novembar 100%

page_text: F
Facilitating the Use of Printing Plates or Rollers in
Metallography.
I, MAX JAFFÉ, of Vienna, in the Empire of Austria, do hereby declare the
nature of my 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 metallography.
In printing, writing or drawing in the usual manner from a plate or roller made
of zinc or other metal it often occurs, that in spite of the plate or roller being
wetted with water each time before inking the same, the ink adheres to the plain
or unengraved portions of the plate or roller which ought to remain free from
colour.
The present invention has for its purpose to wholly obviate this draw-back and
thereby ensure the printing of perfectly correct copies.
According to the said invention, each time before. the plate or roller is inked the
surface of the same is slightly roughened by etching with an acid or corrosive
substance, in order to cause the plain portions between the strokes or lines to
remain wet and thus prevent these portions from taking up the ink. The application
of the etching acid or corrodent is accomplished at the same time as the wetting of
the plate or roller, as the said acid or corroding substance is added to the water
used for wetting. I also add to the water a substance which tends to keep the
plate or roller wet longer than would otherwise be the case.
As corrodents, I use hydrochloric, sulphuric or nitric acid, or perchloride of iron,
and as means for keeping the roughened surface or the plate or roller wet, I use
glycerine and gum-arabic.
To obtain fine and correct copies, I proceed as follows, that is to say:-
As soon as the writing or drawing is transferred upon the plate or roller in the
usual manner, the plate or roller if made of zinc, is etched by means of diluted
hydrochloric, sulphuric or nitric acid, while if made of copper it is etched with a
solution of perchloride of iron. Thereafter printing may be effected by means of
hand-presses, fly-presses or rotary presses.
Every time before the plate or roller is inked, that is to say, every time a copy
is taken, the plate or roller is slightly etched anew and wetted.
The following is the composition of the etching and wetting mixture:-To
1000 parts by weight of the water I add from 2 to 4 parts by weight of nitric or
hydrochloric acid, or from, to 2 parts by weight of sulphuric acid; from 30 to
50 parts by weight of glycerine; and from 7 to 10 parts by weight of gum-arabic.
For copper plates or rollers the acid is replaced by from 2 to 5 parts of perchloride
of iron.
In the trials made the proportions of the ingredients named have given good
results; the quantities of the several additions to the wetting water can, however,
be varied according to the chemical and molecular nature of the metal forming
the plate or roller, and according to the moisture of the air in the printing room.

page_text: Furthermore, it is not indispensable to add both glycerine and gum-arabic to the
wetting water, as either of these substances alone will bring about the desired
effect.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
The improvement in metallography consisting in roughening the plain or
unengraved portions of the surface of the metal plate or roller, by etching these
portions while they are being wetted before inking; said etching and wetting
being performed with zinc plates or rollers by means of a solution consisting of
1000 parts by weight of water, from 2 to 4 parts by weight of nitric or hydro-
chloric acid, or from to 2 parts by weight of sulphuric acid, and from '30 to
50 parts of glycerine, and from 7 to 10 parts of gum-arabic, or either of the
two latter substances, and with copper plates or rollers, instead of the acid, from
2 to 5 parts by weight of perchloride of iron.
.14 נ...
012
2
1000
HASELTINE, LAKE & Co.,
Agents for the Applicant.