An Improved Method of Producing Photographs in Line, Stipple, and the like.
Year: 1893

page_text: Date of Application, 15th June, 1893
Complete Specification Left, 15th Mar., 1894-Accepted, 21st Apr., 1894
PROVISIONAL SPECIFICATION.
An Improved Method of Producing Photographs in Line, Stipple,
and the like.
FRANK STERNBERG Artist and Engraver Hillside Cottage Bushey Herts do
hereby declare the nature of this invention to be as follows:-
The principle of my invention is that of laying a non-actinic etching ground upon
a negative of the subject and scratching lines with a needle through the ground or
removing the ground in places by stipple or scraping, either artistically or
mechanically, so that only those parts of the negative print where the ground has
been removed. The finished print may be used to make a "copperplate" etching
or" typographic" block from by any suitable photographic process. The etching
ground must be of such a colour as will prevent the negative being printed through
by light excepting where it is removed, and when it is to be removed artistically it
must be sufficiently transparent to enable the artist to see the negative through it
whilst he is scratching in the lines &c.
The advantage which I more particularly claim in this invention is the method
of being able to put artistically suitable lines &c. in the various parts of the
subject, which lines &c. will be correctly modified in tone.
Dated this 14th day of June 1893.
FRANK STERNBERG.
COMPLETE SPECIFICATION.
An Improved Method of Producing Photographs in Line, Stipple,
and the like.
FRANK STERNBERG Artist and Engraver Hillside Cottage Bushey 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:-
My invention consists of a method of treating photographic negatives in such a
way that prints taken from them by transmitted light have the appearance of
impressions from copperplate etchings.
My method of obtaining this result is as follows:-
I cover the surface of a negative with a thin film of etching ground or any
equally suitable substance which is capable of obstructing the actinic light
entirely or partially, and at the same time sufficiently transparent to enable the
negative to be seen through it. I hold the negative thus prepared before a
reflected light and then scratch lines or dots through the etching ground;-being
guided in drawing, and the kind of line or stipple required in the various parts, by
the negative which I can see through the etching ground. It is necessary to use a
smooth-pointed needle or dotting tool in order to avoid scratching the negative
itself.
The negative thus treated will print in its proper strength through the lines or
dots thus scratched, and only partially prints, or does not print at all, through the
etching ground remaining upon the negative between the lines or dots.
As no acid is used in this process it is not necessary to use an acid-resisting
etching ground. The liquid etching grounds in common use answer the purpose
well. The etching ground may be smoked or otherwise made more non-actinic in
17

page_text: parts. Aquatint grounds or soft grounds or equally suitable substances may
be used.
I am aware that it has been heretofore proposed to apply a non-actinic film
(which may or may not bear a photographic picture) to a glass plate or other
transparent substance and scratch lines through the film so as to produce fine lines
of clear glass, which would yield a photographic print in lines of one depth of tone
only, and I wish to point out that the lines in a photographic print taken from a
composite negative prepared according to my invention are correctly varied in tone
by the image on the primary negative through which the light must pass in making
the print.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
The herein described method of producing photographic prints in line, stipple
and the like, which consists in coating a photographic negative of the subject with
a non-actinic or partially actinic etching ground or equally suitable substance and
then engraving such subject in line, stipple, or the like in such coating by means
of any suitable tool, whereby a composite negative is obtained which is capable of
producing photographic prints in line, stipple, or the like, of a graduated depth of
tone, substantially as and for the purposes described.
Dated this 14th day of March 1894.