AN IMPROVED MODE OF PRODUCING PRINTING SURFACES
Year: 1853

page_text: LETTERS PATENT to David Bogue, of Fleet Street, in the City of
London, Publisher, for the Invention of "AN IMPROVED MODE OF
PRODUCING PRINTING SURFACES."-A communication.
PROVISIONAL SPECIFICATION left by the said David Bogue at
the Office of the Commissioners of Patents, with his Petition, on
the 25th October 1853.
I, DAVID BOGUE, do hereby declare the nature of the said Invention
for "AN IMPROVED MODE, OF PRODUCING PRINTING SURFACES" to be as
follows:-
This Invention relates to a mode of obtaining a printing surface in
relief on metal plates, which plates will admit of being printed from by
the ordinary typographic press. In carrying out this Invention I first
prepare a polished plate of copper, zinc, steel, or other suitable metal or
mixture of metals, and transfer thereon by the application of pressure
the drawing or print which is required to be reproduced, and enable the
plate to resist the action of corrosive acids at those parts of its surface
which correspond to and lie under the lines, letters, or marks of the
transfer. I next submit the plate to the action of dilute nitric or other

page_text: suitable acid, either by immersing it therein (the back of the plate
having been previously varnished to enable it to resist the action of the
acid), or by building a wall of wax round the edge of the plate, and
covering the plate with the acid. The corroding action I allow to pro-
ceed until the level of the exposed surface is sufficiently reduced to
admit of the plate (when the transfer is cleaned off) being printed from
like a wood engraving
•
By this means I am-enabled-to-reproduce engravings-of-all kinds,
and to prepare plates from which books, when out of print, may be re-
SPECIFICATION in pursuance of the conditions of the Letters Patent
.and of the above-Order, filed by the said David Bogue in the Great
Seal Patent Office on the 29th April 1854."
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,.
DAVID BOGUE, of Fleet Street, in the City of London, Publisher, send
greeting.
1
WHEREAS Her most--Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date, the, Twenty-fifth day of October, in.the.
year of our Lord One thousand eight hundred and fifty-three, in the
seventeenth year of Her reign, did, for Herself, Her heirs and succes-
sors, give and grant unto me, the said David Bogue,' Her special
license that I, the said. David Bogue, my executors, administrators,
and assigns, or such others as I, the said David Bogue, 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 Islanils, and Isle of Man, an Invention for "AN IMPROVED
MODE OF PRODUCING PRINTING SURFACES," being a "communication from:
abroad, upon the condition (amongst others) that I, the said David
Bogue, by an instrument in writing 'under my hand and seal; 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

page_text: 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 David Bogue, do hereby declare
the nature of the said Invention, and in what manner the same 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 mode of obtaining a printing surface in
relief on metal plates; which plates will admit of being printed from by
the ordinary typographic press. In carrying out this Invention I first
obtain or prepare a plate of polished copper, zinc, steel, or other suit-
able metal or mixture of metals, and having removed from the polished
surface every particle of grease by the application thereto of fine pounce
moistened with water, I transfer on to the cleaned polished surface by
means of pressure the drawing or print which is required to be repro-
duced. When transferring a print I prefer to use an impression which
has been recently printed, or if it be an old print that is required to be
transferred, I treat it, after the manner now commonly employed by
lithographic printers prior to making a transfer. A drawing, in order
to be transferred, must be made in lithographic transfer ink, as is well
understood, and the transfer may be effected by applying the pressure
of a lithographic press. I next prepare the plate to resist the action of
corrosive acids at those parts of its surface which correspond to and lie
under the lines, letters, or marks of the transfer, my object being to bite
away or remove so much of the surface of the plate as is not covered
with the ink from the transferred drawing or print, and thereby to pro-
duce a metallic counterpart of the transfer in relief. To. this end I wash
the plate containing the transfer with gum water slightly acidulated
with nitric acid, and after allowing this preparation to remain on the
surface of the plate for about five minutes I sponge the plate over with
clean water. While still wet, I pass over the face of the plate a. litho-
graphic roller charged with ink. composed by preference of the following
ingredients: Bitumen of Judea, powdered very fine with a muller, and.
mixed with boiled linseed oil. The oil. should be of the purest quality,
and previous to being used should be boiled for full an hour, and after-
wards filtered through a felt bag in which. some animal black has been

page_text: placed. For zinc plates instead of the foregoing composition the fol-
lowing may be used:-Lithographic transfer ink and some melted virgin
wax well mixed and ground together.
It will be understood that the lines of the transfer only will take up
the ink, the parts of the plate where the lines of the print or drawing
do not occur having no power to take it up. I next take some resin.
ground to an impalpable powder, and distribute it over the surface of the
plate with a piece of cotton wool or a camel's hair brush, being careful
that it adheres to the inked transfer only, and not to the other portion
of the plate.
Having lightly wiped the plate with another piece of cotton wool in
order to remove the particles of rosin which may have lodged between
the lines of the transfer, I expose the plate to the heat of a spirit lamp
until it becomes lukewarm, and then leave it, say for a couple of hours,
at the expiration of which time it will be ready to undergo the biting
operation..
I
may here remark that great attention is requisite in carrying out
this part of the process, for if too much heat is imparted to the plate the
lines of ink with the rosin coating will spread and destroy the sharpness
and beauty of the transfer; and if the plate is heated too little the ink
and rosin will not combine so thoroughly as to protect the portions of
the plate covered by the transfer from the corroding action of the
acid.
In carrying out the biting process I take by preference some rectified
nitric acid, which I dilute with water to about four degrees Reaumur
for the zinc and steel plates, and to about twelve degrees for the copper.
To this I add a tablespoonful of spirits of wine for each half pint of
acidulated water.
Having covered the back of the plate with a coat of varnish or other
substance which will protect it from the action of the acid solution, I
bathe the face of the plate continuously with the dilute acid by means
of a clean sponge for the space of a quarter of an hour, more or less,
the plate being set in a slanting position to allow of the liquid flowing
away rapidly, after which I pour pure water over the plate to remove
every particle of the acid therefrom. I then wash the plate with an-

page_text: other sponge moistened with gum water, and leave it for five minutes,
after which I re-ink the face of the plate with the roller charged with
the compositions previously described. Having let it stand for another
quarter of an hour I again submit the plate to the action of the acidu-
lated water, and repeat these two operations alternately three, four, or
more times, until the level of the exposed surface of the plate is suffi-
ciently reduced to permit of the protected parts being printed from
as from a stereotype plate. I next clean off the plate with turpentine,
and afterwards well rub it over with charcoal, and it is then ready
to be mounted on a wooden block to bring it to the proper height
for ranging like stereotyped wood engravings with printing types.
Before, however, mounting it on the block I cut away the broad
whites to prevent them from taking ink from the printing roller and
spoiling the impression.
From the above description it will be understood that I am not only
enabled to reproduce engravings of all kinds, but also to prepare plates.
from which books when out of print may be reproduced without the
necessity of resetting the matter.
Having now set forth the nature and object of the Invention of an
improved mode of producing printing surfaces, as communicated to me
by my foreign correspondent, and explained the manner of carrying the
same into effect, I wish it to be understood that under the above in
part recited Letters Patent I claim the process of manufacturing raised
printing surfaces in metal, as above described.
In witness whereof, I, the said David Bogue, have hereunto
set my hand and seal, this Twenty-ninth day of April, in the
year of our Lord One thousand eight hundred and fifty-four.
Witness,
FRED. WALK DEN,
66, Chancery Lane.
DAVID BOGUE. (L.S.)