A New Mode of Preparing Artistic Printing Surfaces.
Year: 1894

page_text: Date of Application, 24th Dec, 1894
Complete Specification Left, 17th Sept., 1895-Accepted, 2nd Nov., 1895
PROVISIONAL SPECIFICATION.
A New Mode of Preparing Artistic Printing Surfaces.
We HUBERT HERKOMER R.A. and ПENRY THOMAS Cox Copper Plate
Printer, both of Bushey in the County of Herts do hereby declare the nature of
this inveution to be as follows:
It is seldom that an artist who has produced a picture, can reproduce it by
engraving or etching, and consequently, when reproduced by others, many of the
artistic touches which can only be effected by the hand of the original artist, and
which give the picture much of its value, are lost.
Now the object of the present invention is to prepare a printing surface in such
a manner that the artistic touches which are obtainable only from the hand of the
original artist, may be faithfully reproduced, without the necessity for further
manipulation, as when photography is employed.
In carrying out this invention we take any smooth surface say a copper plate
and we produce a picture on the plate with a brush or a dabber or both or with
auy other tool preferably a specially prepared medium.
When the picture or design is prepared the surface is dusted over with a
powdered mixture the object being to provide for giving a gram on the picture
which will be reproduced in electiotyping which is the next operation to produce
the artistic printing surface.
The specially prepared medium which we prefer to use is composed of a suitable
vegetable oil, an animal fat which will have the effect of slightly retarding the
drying of the oil it beg necessary that the medium shall remain more or less
moist until the picture is complete in order that the graining medium shall
properly adhere at all points, and a powder to give a body such as German
black or lamp black. These ingredients are thoroughly mixed and ground
together.
The graining medium which we prefer to use is powdered asphaltum and bronze
powder but other materials may be used in place of the asphaltum as for instance
powdered resin or other gum which is dissolvable in turps or spuits.
Dated this 24th day of December 1894.
NEWTON & SON,
Agents for the Applicants.
YOW моно
We UBERT HERKOMER RA and HENRY Tшомае Cox Copper Plate
Printer both of Bushey in the County of Herts 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 object of this invention is to reproduce in any quantity by printing, copies
of a picture as drawn by the original artist, and the invention consists in the

page_text: preparation of a printing surface (by the aid of the ordinary electrotype process)
on which the artistic touches obtainable only from the hand of the artist will be
faithfully and clearly defined.
This result we have already obtained by coating a copper plate such as is used
by engravers with a soft tacky medium to a given depth and then removing or
educing the thickness of the coating at the parts where the lights and middle
tints are required, with a rag a brush or a piece of wood, according to the character
of the artistic touchce lesued, and then treating the surface thus prepared, with a
mixture of granulated substances to receive the electrotype doposit
It will be understood that the removal of the tacky substance with the rag brush
or stick, is the work of the artist and thus it is that the artistic touches before
referred to are obtamed.
Considerable experience has proved to us that this mode of procedure does not
give entire satisfaction, especially in subjects, where a breadth of light or inedium
tones prevail and we have found that by following more nearly the ordinary
practice of the painter in oils, in preparing the pictorial surface, which is to form
the counterpart of the electrotype plate, and in imodifying the composition of the
mediums employed, better results are obtained and it is these important modifea-
tions in the process above referred to, which form the subject of the present
application for a Patent.
The mode of operation and the means to be employed in obtaining printing
sui faces may be thus described.
We provide a copper plate faced with silver for the reception of the picture
which is to be reproduced copper The object of silvering the copper plate is to
prevent the adherence of the copper deposit during the subsequent manufacture
of the plate. Upon this plate the artist will work, as if he were producing a tone
drawing, laying on the inky medium by the aid of a brush or a dabber, sparingly
or otherwise, to produce the varying tints or shadows required to give proper force
and perspective to the picture.
Thus, the lights will be represented by the silvered face of the plate the distances
in the picture, by a sparse application of the medium employed and the deepest
tones by the greatest thickness of medium applied by the artist's brush. The
picture thus produced is, next, to be prepared for the electrotype bath, by giving it
a metallic sui face on which the copper is to be deposited
In order however that the plate when obtained may hold the printer's ink in its
cavities it is necessary to produce what is known as a "gian," in those parts of
the plate which gain must be coniser or finer according to the depth of tit or
tone required for the various parts of the artistic composition
The picture while still tacky is dusted over with a granular substance possessing
electrical conductivity and of varying degrees of fineness for example powdered
asphaltum and bronze powder in equal parts by weight. This bronze powder
should consist of pune copper it having found in practice that the bronze powders
in the market consist of mixed metals the presence of which in the electiotype
bath is liable to set up an electrical action detrimental to the result desned.
This granular composition after careful mixing is placed in a bag of fine muslin
and then dusted over the picture until the work of the artist is completely hidden.
The su plus powder is then removed by a soft camel's hair brush, or its equivalent,
and that which has come into contact with the picture is retained, the coarser grains
being held by the thicker coating of the medium, while the films and thinner parts
secure only the finer grains
The picture in this state is laid aside for some three days to harden and it is then
ready for the bath, care must however be taken that the surface of the picture 18
not touched, as it is liable to injury from even a slight amount of pressure.
The electiotype is produced by electro deposition in the well-known manner,
the picture having been by the dusting over process converted into a properly
metallized surface.
The inky composition or medium which we employ for producing the picture,

page_text: consists, by preference of almond and castor oil mixed with German black, or lamp
black, the castor oil serving to retard the daying of the composition. The
proportions used may be about equal parts by weight of the two oils and German
black or lamp black.
The retention of the tackiness of the picture is especially necessary when a
work of some elaboration is in hand and some two, three, or more days are required to
complete it, the premature hardening of the medium necessarily preventing the
proper attachment of the granulated mixture applied to the picture and thus
rendering much of the artist's labor abortive.
The electrotype of this plate will represent the reverse of the artist's work and
the impressions from the plate will therefore be a correct reproduction of the
picture.
The plate may be used in the state in which it comes from the electrotype bath,
to throw off impressions, but when the artist is familiar with the resources of the
experienced engraver the dry point may be used, or the processes of etching of
mezzotint may be applied, for working up the picture and producing brilliant
artistic effects.
To increase the life of the plate it may be steel surfaced in the manner commonly
practised with respect to engraved copper plates
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim 18.
The mode of producing artistic printing surfaces as described, consisting in
painting on a ground or base a picture in a greasy or tacky medium and surfacing
the same, while still tacky, with a granulat substance possessing electrical
conductivity, removing the excess of the grauular substance and then submitting
the coated picture to an electrotype bath for the production in copper of a
counterpart of the picture.
Dated this 14th day of September 1895.
NEWTON & SON,
Agents for the Applicauts.