AN IMPROVED METHOD OF RETOUCHING PHOTOGRAPHIC NEGATIVES AND POSITIVES
Year: 1874

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane,
in the County of Middlesex, Patent Agent, for the Invention of
"AN IMPROVED METHOD OF RETOUCHING PHOTOGRAPHIC NEGATIVES AND
POSITIVES."--A communication from abroad by Claude Léon Lambert,
of Paris, France.
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 8th May 1874.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature of
the said Invention for "AN IMPROVED METHOD OF RETOUCHING PHOTOGRAPHIC
NEGATIVES AND POSITIVES," to be as follows:-
This Invention relates to a method of improving or retouching
photographic negatives, whether such are taken from nature or are
enlarged reproductions, whereby all retouching of the positive proof on
paper is rendered unnecessary.

page_text: In all processes of the kind heretofore practised it has been usual to
operate either on the positive paper print or on the varnished film of
collodion constituting the negative from which the positive proofs are
obtained. This method is tedious and expensive, especially when
operating on a picture reproduced and considerably enlarged, and more
particularly in the case of portraits in which the grain of the paper
becomes coarser the greater the enlargement. Moreover it can only be
performed by experienced artists, whereas by the improved method of
this Invention the treatment is considerably simplified.
The following is a description of this improved process :-The negative
of large dimensions is first obtained by salts of silver, or carbon and salts
of chromium, in the ordinary manner now in use. If an enlargement
this may be obtained directly from a small positive paper picture or
from a positive proof obtained from the small negative, cither with salts
of silver, or, which is preferable, with salts of chromium specially
prepared for the purpose.
The large negative may be produced in an ordinary camera of large
dimensions, but I prefer the dark room for the purpose as it permits
of overlooking the picture and making any modification deemed
desirable, as will herein-after appear. This large negative after having
been properly exposed, developed, fixed, and finished is covered on both
sides with a sheet of thin paper specially prepared for the purpose, or
any other semi-transparent material capable of retaining the coloring
matter to be afterwards employed. I however prefer this specially
prepared paper of a particular grain, because when placed on either side
of the negative it has the effect of neutralizing by its optical com-
bination the defects due to the material of which it is composed and
which separately exhibits an exceedingly coarse grain. This novel
application alone will in a great measure attenuate the grain which is
always apparent in photographic reproductions from pictures on paper.
It is by acting on these two surfaces covering and enclosing the negative
that the picture printed from the latter may be improved or touched up
in an extremely simple and easy manner, which consists in applying
whenever necessary, either on the collodion side or on the reverse, an
impalpable galvano-plastic pouder or other finely pulverized substance
answering the same purpose. This pouder is most conveniently applied
with a stump. By this means a negative wanting in vigour or harmony
may in a few moments be strengthened and have imparted to it all the

page_text: softness and the effect of the most carefully stumped drawing. Moreover
the effects of light and shade may be modified, toned, or heightened, and
such a high degree of finish imparted as will render any subsequent
retouching of the positive paper print unnecessary, the sharpness of the
lines being restored with the aid of a lead pencil. This treatment may
be performed in a few minutes even for very large surfaces and by
persons completely inexperienced in the art of retouching pictures. The
negative after being thus treated is placed in the pressure frame with a
sheet of ordinary sensitized paper prepared either with salts of silver
or of chromium to obtain a perfect positive.
Should the lines of the negative be sharp or well defined, more
especially in the case of large pictures, they may be softened in the
positive proof by partially printing it, say three-fourths of the time, in
contact with the large negative, and then completing the impression
after having interposed a slicet of very thin glass between the negative
and the paper, or a sheet of any other thin transparent material may be
substituted for the glass.
-
The complete or partial transformation of the backgrounds, as well as
of draperies, hair, dress, or any part requiring to be modified, may thus
be readily obtained in the following manner: On the positive picture
obtained as previously described is applied a sheet of extra thin glass
on which the outline of the subject is traced at á distance of say th of
an inch from the true outlines to be protected from the action of light.
On the mask cut out of yellow paper is then placed another glass of
the same dimensions on which the outlines are similarly traced, but in
this case about 12th of an inch within. In this manner the optical
effect is obtained without showing the line of demarcation and the
background may be toned to harmonize with the subject.
A plain or graduated background may by the same means be replaced
by any other subject, such as a landscape, interior or other adjunct, and
vice versa.
The process herein described may be applied to positives of all
dimensions, and which after being thus treated will serve for the
reproduction of negatives requiring no further retouching.
The Invention thus chiefly consists in the application of a translucid
sheet on each side of a negative or positive, and in the method of

page_text: quickly and readily retouching by operating on these surfaces, whereby
the tedious and expensive retouching of the negative or the positive
proof is dispensed with.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Melville Clark in the Great Seal Patent
Office on the 7th November 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of May, in the year of our
Lord One thousand eight hundred and seventy-four, in the thirty-seventh
year of Her reign, did, for Herself, Her heirs and successors, give
and grant. unto me, the said Alexander Melville Clark, Her special
licence that I, the said Alexander Melville Clark, my executors, admini-
strators, and assigns, or such others as I, the said Alexander Melville
Clark, my executors, administrators, and assigns, should at any time agrce
with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"AN IMPROVED METHOD OF RETOUCHING PHOTOGRAPHIC NEGATIVES AND POSITIVES,"
a communication to me from abroad by Claude Léon Lambert, of
Paris, France, upon the condition (amongst others) that I, the
said Alexander Melville Clark, my executors or administrators, by
an instrument in writing under my, or their, or one of their hands
and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Alexander Melville Clark, do hereby
declare the nature of the said Invention, and in what manner the same.

page_text: is to be performed, to be particularly described and ascertained in and
by the following statement, that is to say:-
This Invention relates to a new method of retouching, applicable to
photographic negatives of any size, whether such are taken from nature
or are enlarged reproductions, and wliereby all retouching of the positive
print on paper is rendered unnecessary.
In all methods of retouching heretofore practised it has been usual to
operate either on the positive paper print or on the varnished film of
collodion constituting the negative from which the positive prints are
obtained. This method is tedious, and expensive, especially when
operating on a considerably enlarged reproduction, and more par-
ticularly when taken from a carte de visite portrait, the grain of whose
paper shows coarser the greater the enlargement. Moreover it can
only be performed, by experienced artists, whereas by the improved
method of this Invention this treatment is considerably simplified.
The following is a description of the improved process-A negative
of large dimensions is obtained with salts of silver, or in carbon with
salts of chromium in the ordinary manner now in use. If I proceed by
enlarging the enlargement may be obtained directly from a small positive
image on paper, or from a transparent positive on glass obtained from
the small negative, either in salts of silver, or, which is preferable, in
salts of chromium specially prepared for the purpose.
66
The large negative may be produced in an ordinary enlarging camera
of large dimensions, but I prefer the dark room for the purpose as it
permits of overlooking the picture and making any modifications deemed
desirable as will hereafter appear. The large negative after having been
properly exposed, developed, fixed, and finished, is covered on both
sides with a sheet of thin paper specially prepared for the purpose with
paraffine, and subjected to great pressure somewhat resembling bank
post paper, and known in France as papier minéral" or any other
semi-transparent material capable of receiving the coloring matter to be
afterwards employed. I however prefer this specially prepared paper of
a particular grain known as "papier pelure végétal" because it has the
effect, when placed on either side of the negative, of neutralizing by its
optical combination the defects due to the material of which it is com-
posed, and which seen separately exhibits an exceedingly coarse grain.
This novel application will in a great measure attenuate the grain which

page_text: is always apparent in photographic reproductions from images on paper.
It is upon these two surfaces which cover and enclose the negative that
the retouching of the picture may be effected in an extremely simple
and easy manner, by applying, wherever necessary, either on the
collodion side or on the other side, an impalpable galvano-plastic powder
or other finely divided substance answering the same purpose. This
powder is most conveniently applied with a stump. By this means a
negative wanting in vigour or harmony may in a few moments be
strengthened and have imparted to it all the softness and the effect of
the most carefully stumped drawing. Moreover the effects of light and
shade may be modified, the most. perfect degree of softness and an
incomparable finish imparted to the picture, so that any subsequent
retouching of the positive paper print is dispensed with, the sharpness
of the lines being restored with the aid of a black lead pencil. This
treatment may be performed in a few minutes even upon very large
surfaces and by persons completely inexperienced in the art of retouching
and of drawing. The negative after being thus treated is placed in the
printing frame with a sheet of ordinary sensitized paper (prepared either
with salts of silver or of chromium) whereupon a perfect positive image
is obtained.
Should the lines of the primary "cliché" be too strong or well
defined, more especially in the case of large pictures, they may be
softened in the positive image by printing it partially, say three-fourths
of the time, in contact with the large negative, and then interposing a
sheet of very thin glass between the negative and the paper, or before
completing the impression a sheet of any other transparent or opaline
material not exceeding 0.04 of an inch in thickness may be substituted
for the glass.
The complete or partial transformation of the backgrounds as well as
of the draperies, hair, dress, or any part requiring to be modified may be
readily effected in the following manner :-On the positive image
obtained as previously described is applied a sheet of extra thin glass on
which the outline of the subject is traced at a distance of say 125 of an
inch outside of the true outlines to be protected from the action of light.
On the mask cut out of yellow paper is then placed another glass of
medium thickness of the same dimensions on which the outlines are
similarly traced, but in this case about th of an inch within the true
outlines. In this manner the optical effect is obtained without showing

page_text: the lines of demarcation, and the background may be darkened or
lightened to harmonize with the subject.
A plain or graduated background may by the same means be replaced
by a landscape, interior or other adjunct, and vice versa.
The process herein described may be applied to transparent positives
of all dimensions, which after being thus treated will serve for the
reproduction of negatives, no further retouching being required.
Having described the nature of the Invention and the manner of
performing the same I declare that what I claim as the Invention to be
protected by the herein-before in part recited Letters Patent is, the
method of applying a semi-translucid sheet on each side of a negative or
positive, and of quickly and readily retouching by operating on these
surfaces, as hercin specified, whereby the tedious and expensive.
retouching of the negative itself or of the positive print is dispensed
with.
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and seal, this Sixth day of November,
in the year of our Lord One thousand eight hundred and seventy-
Witness,
HARRY SWALES,
53, Chancery Lane,
London.
A. M. CLARK. (L.S.)