AN IMPROVED PROCESS OF ENGRAVING
Year: 1864

page_text: LETTERS PATENT to Paul Emile Placet, of Paris, Rue Garanciere,
No. 8, Civil Engineer, for the Invention of "AN IMPROVED PROCESS OF
ENGRAVING."
Sealed the 3rd March 1865, and dated the 8th September 1864.
PROVISIONAL SPECIFICATION left by the said Paul Emile Placet at
the Office of the Commissioners of Patents, with his Petition, on the
8th September 1864.
I, PAUL EMILE PLACET, of Paris, Rue Garanciere. No. 8, Civil Engineer,
do hereby declare the nature of the said Invention for "AN IMPROVED
PROCESS OF ENGRAVING," to be as follows:-
The object of my Invention is to produce by means of photography designs
in relief or sufliciently prominent or resisting for employment as a reserve
(reserve) in the different methods of engraving. I spread on a metal plate
a layer or coating of a mixture composed of albumen (say 100 parts, more
or less), bichromate of potassa or of ammonia, say 10 parts, and a small
quantity of glycerine or sugar, a few drops of ammonia may also be added to
clear the mixture. After drying I expose this plate to the action of light
[Price 8d.]
'

page_text: under a plate (cliche) or surface carrying the design to be engraved. I then
dip it in water. The design appears in relief, forming a "reserve." and the
metal is plain or bare wherever the light has not acted upon it. Instead of
albumen any animal or vegetable matters may be employed, such as bitumen,
resin, gum, gelatine, dextrine. gluten, casein, and others, rendered sensitive to
the action of light by one or several salts of gold, silver, uranium, chromium,
iron, or by sulphurets, iodurets. or other like agents. The parts not covered or
"reserved" by the matter forming the design may be treated in many ways.
according to the object for which they are intended. (In some cases before
commencing the other operations it is well to apply powdered resin to the
plate.). They may be covered with gold, in order that the design may be
acted on by the electro-galvanic process. or by acids or other agents: they
may be amalgamated and brought up in relief by means of amalgams of
copper, or of metals fusible at a low temperature: they may be covered with
platinum, iron, or oxidized copper: the design itself is removed by any con-
venient agent, it is then amalgamated and brought up in relief as above
described by means of copper amalgams or otherwise: or the plate may be
inked after having been amalgamated, and impressions may then be struck off
as in ordinary lithographic printing; the mercury repels the ink, and acts as a
reserve (epargne). Or the plain or bare parts may be iodized, and then inked
to enable impressions to be taken as in lithography: the ink remains only on
the indized parts; this inking may even be performed without indizing the
plate. Or the plain or bare parts may be covered by the electro-galvanic pro-
cess with a layer more or less thick of metal, the design acts as the reserve.
and the result according to the thickness of the metal deposited, and the plate
(cliche) employed is an engraved plate or block in intaglio or in relief, which
may be employed in printing or for ornamenting. If the action of the electro-
galvanic process be prolonged the deposit covers the design by degrees, and
finally altogether; on afterwards separating the two plates there will be found
sunken or in intaglio a perfect reproduction of the design, which may be
employed in printing. The "reserve" (reserve on epargne) obtained as above
described may be applied in numerous ways, for example, the metal partially
deposited on the plate may be brought up in relief by means of collodion,
varnish, gelatine, or other similar material whereby a photographic plate is
obtained, in which the black parts (noirs) are formed by the deposited metal.
This design formed in metal may he employed for a variety of purposes.
14
"
By the process above described I obtain photographically on a metal surface
or other surface. such as glass or porcelain, a design forming a
(reserve) to the agents employed to bite out or to deposit metal. By applying
reserve

page_text: the usual methods of engraving to this photographic "reserve" I obtain many
of the kinds of engraving in intaglio and in relief used in printing and
ornamenting.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Paul Emile Placet in the Great Seal Patent Office on the
8th March 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PAUL. EMILE
PLACET, of Paris. Rue Garanciere, No. 8, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of September. in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-eighth year of
Her reign, did, for Herself. Her heirs and successors, give and grant unto
me, the said Paul Emile Placet. Her special licence that I. the said Paul
Emile Placet. my executors, administrators, and assigns, or such others as
I, the said Paul Emile Placet, my executors, administrators, and assigns,
should at any time agree 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 PROCESS OF ENGRAVING," upon the condition (amongst others)
that I, the said Paul Emile Placet. 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 Paul Emile Placet, do hereby declaro
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:-
The object of my Invention is to produce by means of photography designs
in relief or sufficiently prominent or resisting for employment as a reserve
(reserve) in the different methods of engraving. I spread on a metal plate a
layer or coating of a mixture composed of albumen (say 100 parts, more or
less). bichromate of potassa or of ammonia (say 10 parts), and a small
quantity of glycerine or sugar, a few drops of ammonia may also be added to

page_text: clear the mixture. After drying I expose this plate to the action of light
under a plate (cliche) or surface carrying the design to be engraved, I then
dip it in water. The design appears in relief forming a reserve, and the metal
is plain or bare wherever the light has not acted upon it. Instead of albumen
any animal or vegetable matters may be employed. such as bitumen, resin.
gum, gelatine. dextrine, gluten, casein, and others rendered sensitive to the
action of light by one or several salts of gold, silver, uranium, chromium, iron,
or by sulphurets, iodurets, or other like agents. The parts not covered or re-
served by the matter forming the design may be treated in many ways, according
to the object for which they are intended. (In some cases before commencing
the other operations it is well to apply powdered resin to the plate to form a
ground.) They may be gilt. in order that the design may be acted on by the
electro-galvanic process, or by acids or or other agents: they may be amal-
gamated and brought up in relief by means of amalgams of copper, or of
metals fusible at a low temperature: they may be covered with platinum.
iron, or oxidized copper; the design itself is removed by any convenient
agent, it is then amalgamated and brought up in relief as above described by
means of copper amalgams or otherwise; or the plate may be inked after
having been amalgamated, and impressions may then be struck off as in ordi-
nary lithographic printing. the mercury repels the ink and acts as a reserve
(epargne). Or the plain or bare parts may be iodized, and then inked to
enable impressions to be taken as in lithography, the ink remains only on the
iodized parts; this inking may even be performed without iodizing the plate.
Or the plain or bare parts may be covered by the electro-galvanic process with
a layer more or less thick of metal. the design acts as the reserve, and the
result according to the thickness of the metal deposited. and the plate (cliche)
employed is an engraved plate or block in intaglio or in relief, which may be
employed in printing or for ornamenting. If the action of the electro-galvanic
process be prolonged the deposit covers the design by degrees, and finally
altogether; on afterwards separating the two plates there will be found sunken
or in intaglio a perfect reproduction of the design, which may be employed in
printing. The reserve (reserve ou epargne) obtained as above described may
be applied in numerous ways, for example, the metal partially deposited on
the plate may be brought up in relief by means of collodion, varnish, gelatine,
or other similar material whereby a photographic plate is obtained, in which
the black parts (noirs) are formed by the deposited metal. This design formed
in metal may be employed for a variety of purposes.
By the process above described 1 obtain photographically on a metal
surface or other surface, such as glass or porcelain, a design forming a reserve

page_text: (reserve) to the agents employed to bite out or to deposit melal. By applying
the usual methods of engraving to this photographic reserve I obtain many
of the kinds of engraving in intaglio and in relief used in printing and
ornamenting.
In witness whereof, I, the said Paul Emile Placet, have hereunto set
my hand and seal, this Twenty-second day of February. One thousand
eight hundred and sixty-five.
Witness,
0
CH. ARMENGAUD,
Ing" Civil,
Boulev de Strasbourg, 23,
a Paris.
P. E. PLACET. (L.S.)