AN IMPROVED METHOD OF PRODUCING COPIES OF DRAWINGS, ENGRAVINGS, OR OTHER DESIGNS
Year: 1880

page_text: "
LETTERS PATENT to Edmund Edwards, of the Firm of Edwards and Co.,
Patent Agents and Engineers, of 40, Southampton Buildings, in the County of
Middlesex, for an Invention of 'AN IMPROVED METHOD OF PRODUCING
COPIES OF DRAWINGS, ENGRAVINGS, OR OTHER DESIGNS." A communication
from abroad by Maurice Tilhet, of 18, Rue de la Banque, Paris, in the Republic
PROVISIONAL SPECIFICATION left by the said Edmund Edwards at the
Office of the Commissioners of Patents on the 26th November 1880.
EDMUND EDWARDS, of the Firm of Edwards and Co., Patent Agents and
Engineers, of 40, Southampton Buildings, in the County of Middlesex.
"AN
IMPROVED METHOD OF PRODUCING COPIES OF DRAWINGS, ENGRAVINGS, OR OTHER
DESIGNS." [A communication from abroad by Maurice Tilhet, of 18, Rue de la
Banque, Paris, in the Republic of France.]
This Invention has for its object a novel method of reproducing copies of all
kinds of drawings or other designs, and it is applicable to the reproduction of such
copies upon all kinds of paper, and either in black, red, blue, green, or any other
colour.
In order to put the Invention in operation the paper upon which the design is
to be reproduced in order to prepare a negative copy is first passed through a
bath composed of the following materials in about the proportion given, that is to
SAY-
White soap
Alum
Flanders glue
-
30
30 parts by weight.
do.
40
do.
The whites of
eggs
beaten up
4
10
do.
Glacial acetic acid
-
do.
Alcohol at 60 degrees
-
10
do.
Water
- 500
do.
The paper, after leaving this bath is then passed through a second bath composed

page_text: In order to prepare positive paper for the prints a bath is used similar to the
last, but without the umber, for which black pigment is substituted.
Or to obtain coloured proofs instead of black ones the black pigment is replaced
by a pigment of red, blue, or any other desired colour. To prepare the copies the
design or drawing is placed in an ordinary photographic printing frame, the back
of the design being next to the glass, and a sheet of negative paper prepared in the
way first described is placed in contact with it.
The frame is then exposed to light, two minutes exposure being sufficient in
. good weather. The sensitive paper is then removed from the frame in a dark
place and is placed in water when the design becomes visible in white, and the
paper is then allowed to dry.
In order to obtain positive pictures from the negative thus prepared, the latter
is placed in the printing frame with a sheet of the positive paper in contact with
it, and after exposure to light for a sufficient time, that is to say, about two
minutes, the positive paper is removed in a dark place and is plunged into water
which removes the part of the pigment which has not been affected by the light
without its being necessary to touch it.
Any number of copies of the design or drawing may be produced by the
novel method described upon any kind of paper, and in any colour or colours.
The proportion of the different materials used to prepare the baths as above 1
described may be varied to suit varying circumstances.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edmund Edwards in the Great Seal Patent Office on the 26th
May 1881.
EDMUND EDWARDS, of the Firm of Edwards and Co., Patent Agents and
Engineers, of 40, Southampton Buildings, in the County of Middlesex.
"AN
IMPROVED METHOD OF PRODUCING COPIES OF DRAWINGS, ENGRAVINGS, OR OTHER
DESIGNS." A communication from abroad by Maurice Tilhet, of 18, Rue de la
Bank, Paris, in the Republic of France.
This Invention has for its object a novel method of reproducing copies of all
kinds of drawings, engravings, or other designs, and it is applicable to the repro-
duction of such copies upon any kind of paper, and either in black, red, blue, green,
or any other colour.
In order to put the Invention in operation the paper upon which the design is
to be reproduced in order to prepare a negative copy is first passed through a bath
composed of the following materials in about the proportions given, that is to
sayWhite soap, 30 parts by weight; alum, 30 parts; Flanders glue, 40 parts;
the whites of eggs or albumen beaten up, 10 parts; glacial acetic acid, 2 parts;
alcohol at 60 degrees, 10 parts; water, 500 parts.
The paper, after having been removed from this bath, is then passed through a
second bath composed as follows:-Burnt umber ground in alcohol, 50 parts by
weight; black pigment, 20 parts; Flanders glue, 10 parts; water, 500 parts;
bichromate of potash, 10 parts.
The paper having been thus treated must be kept when dry in a dark place.
In order to prepare positive paper for the prints a bath is used similar to the last,
but without the umber, for which black pigment is substituted. Or if it is desired
to obtain coloured proofs instead of black ones the black pigment is replaced by a
pigment of red, blue, or any other desired colour.
To prepare the copies the design or drawing is placed in an ordinary photo-
graphic printing frame, the back of the design being next to the glass, and a
sheet of negative paper prepared in the way first described is placed in contact
with it.
The frame is then exposed to light, two minutes exposure being sufficient in good
weather. The sensitive paper is then removed from the frame in a dark place and
is placed in water, when the design becomes visible in white, and the paper is then
allowed to dry.
In order to obtain positive pictures from the negative thus prepared the latter
is placed in the printing frame with a sheet of the positive paper prepared in the
manner above described in contact with it, and after exposure to light for a
sufficient time, that is to say, about two minutes, the positive paper is removed in
a dark place, and is plunged into water which removes the part of the pigment
which has not been affected by the light, without its being necessary to touch it.
Any number of copies of the design or drawing may be produced by the novel
method described upon any kind of paper, and in any colour or colours.
The proportions of the different materials used to prepare the baths as above
described may be varied to suit varying circumstances, such as the weather and
the character of the design, or of the paper.
Having now described my Invention and the manner in which it is to be
performed, I claim,-
1. In the preparation of negative paper for reproducing drawings and designs,"
the two baths consisting, first, of white soap, alum, Flanders glue, whites of eggs or
albumen beaten up, glacial acetic acid, alcohol, and water; and second, of burnt

page_text: umber ground in alcohol, black pigment, Flanders glue, bichromate of potash, and
water, all in about the relative proportions described.
2. In the preparation of positive paper for reproducing drawings and designs
from negatives upon paper prepared in the said baths, a bath consisting of black or
coloured pigment, Flanders glue, bichromate of potash, and water, all in about the
relative proportions described.
In witness whereof, I, the said Edmund Edwards, have hereunto set my
hand and seal, this 23rd day of May, in the year of our Lord One
thousand eight hundred and eighty one.
EDMUND EDWARDS. (LS.)