IMPROVEMENTS IN THE PRODUCTION OF RELIEF DESIGNS ON METALLIC SURFACES FOR GENERAL PRINTING, GAUFERING, AND EMBOSSING PURPOSES
Year: 1861

page_text: PROVISIONAL SPECIFICATION left by Marc Antoine François Mennons
at the Office of the Commissioners of Patents, with his Petition, on the
9th December 1861.-A communication from François Debons; and
Théobald Denny, residing at No. 48, Rue Beauregard, Paris, France.
I, MARC ANTOINE FRANÇOIS MENNONS, of the British and Foreign Patent
Offices, 39, Rue de l'Echiquier, Paris, in the Empire of France, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE PRODUCTION
OF RELIEF DESIGNS ON METALLIC SURFACES FOR GENERAL PRINTING, GAUFERING,
AND EMBOSSING PURPOSES," to be as follows:
This Invention consists in an improved series of processes by means of which
designs in relief for printing, gaufering, and embossing may be produced on
metallic surfaces of all kinds with greater economy and facility than by the
ordinary modes of etching and engraving.
In order to avoid interruption in the course of the following description,
I will here. specify the different preparations by aid of which these processes
are carried out, and hereafter refer to them by their numbers only.
Rectified benzine
No. 1. Varnish.
Caoutchouc, as pure and white as possible, in sufficient
quantity to saturate and leave an excess undissolved.
twenty ounces.

page_text: The mass is then heated for about fifteen minutes to from 70° to 80° (centi-
grade) and left to cool.
The solution thus formed is strained through any suitable close tissue, after
which a quantity of finely ground zinc white, or other powder of like nature, is
intimately incorporated. The proportion of white powder added in this way
should be such that, on allowing to repose after thorough incorporation, a
deposit to the depth of about half an inch may be found. at the bottom of the
solution. The white varnish thus prepared is preserved in long-necked bottles,
and should be well shaken when about to be used.
Melted and thoroughly incorporated over a slow fire, after which is added
a sufficient quantity of fine lampblack to give to the mass a blackish tinge.
No. 5. Electrotype deposit bath.

page_text: The wax is first melted over a slow fire in a clean earthenware vessel, and the
powdered bitumen is gradually added and thoroughly incorporated. The
tallow, melted apart; is then poured in, the mass being constantly stirred:
No. 10 Acid solution for etching in lieu of the electrotvné bath
The general details of manipulation being, with the exceptions hereafter
noted, the same for all metals, I will here confine myself to a description of
the improved processes as applied to zinc-plates.
The face of the plate to be operated on being thoroughly polished; is
coated as uniformly as possible with the varnish No. 1, and is heated to from
60° to 80° (Cent.), in order to volatilise the solvents of the caoutchouc: The
coating being thus dried, the plate is laid upon a cast-iron table, heated to
about 120° (Cent:), by which the most volatile constituents of the caoutchouc
are carried off, leaving an adherent layer of varnish, which finally attains a

page_text: straw yellow tint, when the plate is set aside to cool. In this state the
design is traced by means of a pen or other suitable point of sufficient hardness
to cut sharply through the coating of varnish, but not hard enough to act on
the metallic surface beneath. Should any defects be found on examination
to exist in the design thus applied, the faulty parts may be stopped out with
the same varnish, which is caused to adhere and set by means of a hot iron
held at a certain distance from the plate, or by aid of a spirit or gas lamp. The
varnish being dried is traced over as before to complete the design. The surface
thus prepared is then uniformly coated with the ground-protecting solution
No. 2, laid on by a soft squirrel or camel-hair brush, or a soft plug of well-carded
cotton. This done, the excess of wax which may have remained in certain
parts of the plate is removed by the clearing solution No. 3, which is passed
lightly over the surface by means of a soft brush. In order to remove the
liquid which may have lodged in the design, the surface is lightly rubbed.
over with a small plug of cotton until all the traced lines are completely dried
and cleared out. Instead of the solutions Nos. 2, 3, the coating No. 4 may
be employed to protect the grounds.. This compound being melted is applied
in the same manner to the plate, which is afterwards laid on a metallic table,
heated to from 100° to 110° (Centigrade). The excess of fatty matter, which
is thus kept in fusion, is removed by -means of a roller covered with flannel
or other absorbent tissue passed lightly over the surface. After this a clean
roller of similar kind is passed over the plate, the lines of which are finally
cleared from the last trace of fatty matter by a broad soft brush or plug of
cotton carried lightly and quickly to and fro over the the surface. The perfect
clearness of the lines forming the design is then tested by means of a small
quantity of finely ground graphite, red peroxide of iron, lampblack, or other
analogous powder rubbed lightly.over the plate, to which it. adheres in those
parts which may still have retained the fatty matter. A metallic conductor
is then secured to the plate, the obverse and edges of which are coated with
an insulating varnish of any suitable kind. This done, the plate being con-
nected with the zinc element of a Daniell's, Smee's, or other constant voltaic
battery, is passed to an ordinary electrotype trough of suitable form and
dimensions, charged with the solution No. 5, in which is immersed a sheet of
copper_of_corresponding surface communicating with the opposite pole. The
action of the voltaic current, which should be very feeble, is continued for
about ninety minutes, during which the copper solution should be kept at a
temperature of from 50° to 55° (Cent.) In this operation the unprotected
lines composing the design are filled up by a thin sharp deposit of copper
adhering perfectly to the surface of the plate, which on being withdrawn from

page_text: copper
the bath is freed from its varnish by careful rubbing with the cleansing
compound No. 6. The design in.relief, thus brought to view is found to be
the exact reproduction of that traced on the varnish, the lines: being neither
thickened nor fined down to any perceptible extent. The plate. being then
ready for the ground etching, is connected with the anode of the battery,_
and immersed in the bath No. 7, in which is placed a clean sheet of
in communication with the zincode. Under the action of the current the
surfaces unprotected by the copper, deposit are dissolved away, molecule by
molecule, with the utmost regularity, the equivalent of the the metal thus
reduced being precipitated on the plate forming the opposite pole. During
this operation, which generally occupies but a few minutes, the plate should.be
from time to time removed from the bath, and its surface cleaned off
with a plug of soft cotton. When the grounds have been eaten out to
the depth of from both to th; of an inch the plate is removed from
the bath, washed, and carefully dried by means of fine tripoli, or other
powder of like 'nature, the remains of which are cleared off by a plug
of soft cotton. The entire surface is then covered with the mineral paste
No. 8, which, fills up all the blanks to the level of the relief lines, and
which, when dry, is removed from the top surface of these lines..by. means
of, an ivory, bone, wooden, or other suitable tool... The lateral surfaces
of the lines are: also laid bare by means of a small flat plug covered
with soft leather and charged with fine tripoli, the remains of which are after-
wards cleared off by a camel-hair brush. The progress of the work may then
be appreciated by aid of a magnifying glass. It will be understood that the
etched surfaces are left covered in the operation; above described, the only
parts cleared off being the top and lateral surfaces of the lines in relief:
Should any of the coating be accidentally.removed from the grounds, it may
be replaced by. a. further supply of paste laid on with a camel-hair pencil:..
These several operations being terminated, a sheet of smooth paper, cardboard;
or parchment is uniformly coated on one side with the adhesive compound
No. 9, and being applied to the face of the plate, is slightly rubbed.over.the
back. In this process the uncovered top and lateral surfaces of the relief
linės are coated, with the wax mixture, to which, on the other hand, the
mineral paste adheres with sufficient tenacity to be entirely carried off on the
removal of the.
On the reliefs thus: covered with waxy matter is
paper..
sprinkled a quantity of "finely powdered resin, the excess of which is cleared
off by a soft brush. The plate is then laid upon a well levelled tablet of
stone, marble, or metal gradually heated, to the temperature required. for the
fusion of the resin, which. in liquifying forms, a uniform.coating over the top.

page_text: and lateral surfaces of the reliefs; this done,' the unprotected grounds are
attacked either by the battery, as above, or by suitable acids (such as by the
solution No. 10), and are eaten out to the depth of about th of an inch..
For the blanks or wide spaces, it may be necessary to deepen the etching, in
.which case the parts to be protected are stopped out by resinous matters spread
upon paper, and applied as above; after this the acid or battery action is
repeated till the desired effects are obtained. The plate is then ready for use.
If so desired, the processes above enumerated may be modified as follows:
In taking the plate when the copper deposit is effected, the caoutchouc varnish
removed, and the metallic surface cleaned off, the copper relief lines represent
the design and the uncovered zinc the parts to be hollowed out; in this state
the plate may be employed to form in itself a voltaic couple. To this end it
is immersed in the etching solution No. 11, by which the zinc is rapidly eaten
out in those parts unprotected by the copper lines which form the design.
It may be observed, that any other solution capable of attacking the zine
grounds while leaving the copper surfaces untouched may be substituted to
the above, which, however, has been found to give the best results in practise.
During this process the copper is precipitated from its solution on the relief
lines of the design in the form of a pulverulent deposit, which is sufficiently
compact to prevent the free acids from attacking the lateral surfaces; the
etching should not, however, be carried beyond Tooth or 5th of an inch.
At this point the operation is pursued in the following way :-A small elastic
plug covered with a soft material, such as caoutchouc, is smeared with a
mixture composed of virgin wax and fine lampblack or red peroxide of iron,
kept in a half melted state on a heated tablet of marble, stone, or metal. This
mixture is dubbed over the engraved surface after the first etching, the plate
being at the same time slightly heated to add to the uniformity of the coating,
care being taken to avoid forcing the wax into the hollow lines while covering
those in relief; it is impossible, however, to avoid touching the wide spaces,
but when this happens it is always at th of an inch at least from the edge
of the relief. In all cases the wax can be removed by any suitable scraper
from. the parts which are required to remain unprotected. The surface thus
waxed is then sprinkled over with finely powdered and sifted resin, the plate
being kept slightly heated in order to keep the wax in-a-semi-fluid-state:
This done the plate. is allowed to cool, and the resin which may not have
adhered to the wax coating is removed by a soft brush, the stray particles
being entirely cleared from the parts to be bitten out. The plate is laid on a
heated tablet in order-to fuse the resin deposited as above, which mingling
with the wax, flows over. the upper and lateral surfaces of the relief lines.

page_text: The plate.is then left to cool, and is afterwards immersed in the acid solution,
by which it is.etched out in its unprotected parts to the depth of th of, an
inch; this done, it is again laid on a heated tablet, and the operator passes
over the relief lines the point of a pencil formed of virgin wax and red
peroxide, of, iron. In this process, the hollow parts of the design, with the
exception of the most closely. set lines, are left untouched.; The powdered
resin is then again 'sprinkled over, the waxed plate and is fused jasy before,,
forming an impervious, varnish on the parts of, the, design which are to be
protected. The plate is then re-exposed to; the acid: solution, washed off-in
cold water, and the same operations of waxing and etching,are, repeated; until
the design is finished off. When dissolving out the large blanks, the remainder
of the design is: protected by the composition No. 12; applied in fusion to the
heated plate by, means of a camel-hair brush.
Having thus described the application, of the Invention to the treatment of
zinc surfaces, I will now point out the modifications to which the other metals
in most common.use give rise..
>
For iron or steel surfaces the design-is formed in copper as above described,
but in etching out the grounds the zinc battery solution No. 7 is replaced by.
the following saturated solution of sulphate of iron: Three-quarters of a pint
saturated solution of nitrate of ammonia, one-quarter of a pint when the
battery is dispensed with...
The etching solution No. 10 is replaced by
Water.
Nitric acid
Hydrochloric acid
...ten ounces
six.ounces:
four ounces.
When the coppered plate is employed. to form of itself the voltaic: couple; the
solution No. 11 is replaced by
Silver
Nitric acid.
1°
one hundred grains dissolved in
Saturated solution of sulphate of iron
Water.
ten ounces.
thirty ounces.
three ounces..
To each ten ounces of which combination is added.
"
Nitrous acid-
Sulphuric acid
two ounces.
one ounce.
For copper surfaces the caoutchouc varnish is applied, and traced .as-above
described, but instead of copper the design in relief is formed by the deposit
of silver from a battery solution of cyanide. of silver, gauging from 2° to -3°
(Beaumé).

page_text: The succeeding etching operation is effected in a saturated solution of nitrate
of copper, and the remaining processes are carried out as above. If desired,
the wide hollows may be etched out with dilute nitric acid or solution of nitrate
of silver.
For brass the manipulation is substantially the same as for copper, the only
difference being that the first etching is performed by a saturated solution of
one part nitrate and one part sulphate of copper.
For surfaces in aluminium, lead, tin, and their alloys, the manipulation is
the same as above described, the etching being performed by solutions having
one of these metals for base.
For silver the design is formed of either gold or iron, and the etchings are
effected by the battery with a solution of cyanide of silver, gauging from 2° to
3° (Beaumé).
For gold the design is formed of iron reduced from a battery solution
composed of―
Pure sulphate of iron
Nitrate of ammonia
Water...
ten ounces.
•
thirty ounces.
one hundred ounces.
The etchings are effected by a battery solution of cyanide of gold, gauging
from 2° to 3° (Beaumé).
The metallic surfaces prepared as above described may, as before stated, be
applied to general printing and embossing on paper, woven fabrics, and other
matters, as also to the gaufering, gilding, and otherwise ornamenting of leather
and similar products.
I should repeat, in conclusion, that the different compounds and re-agents
above enumerated may in many cases be modified or replaced by others of
like nature, although those prepared as described have been found to give the
best practical results.