A. Process for Chromo-lithographic Printing Direct on Sheet Metal Plates.
Year: 1890

page_text: Date of Application, 2nd May, 1890
Complete Specification Left, 27th Jan., 1891-Accepted, 2nd May, 1891
PROVISIONAL SPECIFICATION.
A. Process for Chromo-lithographic Printing Direct on Sheet Metal
Plates.
1, August RUDOLF BÖTTCHER Junior of Leipzig in the Empire of
Germany, Manufacturer, do hereby declare the nature of this invention to be as
follows:-
The object of this invention is a process for producing chromo-lithographic
prints direct on sheet metal plates in contradistinction to the method hitherto
known by which the designs or pictures are first printed on transfer paper and
hence transmitted to the tin plates, which is not only a time-wasting process but
also results in many waste or useless copies.
The improved process consists of a series of consecutive proceedings, viz. :
Glue or gelatine is soaked in cold water. Subsequently two units of weight of
gelatine or glue are put into a linen bag, which is then suspended in a vessel
containing four units of weight of water. This water is heated until the gelatine
or glue is dissolved in the water whereby all impurities are retained within the
linen bag. To this solution are added three units of spirits, eight units of
permanent white" or fine whitening and one unit of glycerine and the whole is
boiled in a covered vessel.
"
The sheet metal plate to be treated is given a uniform coat of copal lac diluted
with turpentine. This lac must be of a very tenacious consistency to enable it to
stand all bendings of the plate during the work without coming off or breaking.
Subsequently the plate is left to dry until the lac is still slightly sticky, when it is
coated once or twice uniformly with the first mentioned solution or mixture by
means of soft brushes and then dried in a moderately heated, dust-free room. The
coating substance however must be kept warm continually. The sheet metal plate
thus prepared is ready for receiving chromo-lithographic printing. The printing is
done, as is usual, with paper, by means of a lithographic,-hand, or steam press.
After the printed colours are thoroughly dried, the plates are covered with an
additional fine colourless lac, subsequently dried in the oven and are then ready to
be made into tin boxes, placards and such like.
-
The chromo-lithographic prints produced on the tin sheets by means of the
improved process are eminently distinct and fine.
Dated this 2nd day of May 1890.
COMPLETE SPECIFICATION.
A Process for Chromo-lithographic Printing Direct on Sheet Metal
Plates.
I, AUGUST RUDOLF BÖTTCHER Junior of 17 Thomasius Strasse Leipzig
in the Kingdom of Saxony, Empire of Germany, Manufacturer, do hereby declare
the nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
This invention relates to an improved process for chromo-lithographic printing
and has for its purpose to allow such prints to be transmitted direct to sheet metal
plates.
The method hitherto applied for the transfer of chromo-lithographic prints to
metal plates is very troublesome and time-wasting, the designs or pictures being

page_text: first printed on transfer paper and then transmitted in the sheet metal plates, which
method, not to speak of the great waste of time, resulted in a great many useless
piecus.
A. material difference in the printing of sheet metal plates is produced by the
application of the improved process, consisting in a series of consecutive manipula-
tions, which may be understood from the following explanation.
Glue or gelatine is stoeped in cold water. Two units of weight of gelatine or
glue are then poured into a linen bag; the latter is suspended in a receptaclu
containing four units of weight of water, which is then heated, until the gelatine or
glue as the case may be has dissolved in the water and thereby all impurities are
retained in the linen bag. Subsequently three units of spirits, eight units of
permanent white or fine whitening and one unit of glycerine are added to said
solution and the whole is boiled in a covered vessel.
26
"
The sheet metal plate to be imprinted is coated as uniformly as possible with
diluted copal lae, or varnish, e. a solution of copal resin in hot turpentine oil.
Said lac must however be very tenacious to allow it to participate in all bendings
of the metal plate while being treated, without coming off or breaking. The plate
is now left to dry until the lae is still slightly sticky. Subsequently the sheet metal
plate treated as above is conted uniformly once or twice as may be required, with
the first mentioned solution by aid of soft brushes and then allowed to dry in a
moderately heated dust-free space. The coating sub-tance is however to be kept
continually warm. The sheet metal plate prepared as herebefore described, is now
ready to receive the chromo-lithographic prints.
The printing on the prepared metal plates is effected in the ordinary manner as
with paper, by means of a lithographic-hand, or steam-press. After the imprinted
colours have been thoroughly dried, the metal plates are given an additional coating
of a fine colourless lac, then dried in the oven, whereupon they are ready to be
formed into tin receptacles, placards or the like.
By the application of the herebefore describal printing process, beautiful and
distinct chromo-lithographic prints on sheet metal plates is produced, such as could
hitherto be attained only by irans of difficult transfer processes.
Having now partienlarly described and ascertained the inture of this inven
tion and in what manner the same is to be performed, 1 declare that what I
claim is:
i.
**
A process for direct imprinting of chromo-lithographie pictures or the like on
sheet metal plates consisting in first providing the plates with a coat of diluted
copal lae, subsequently coating them when nearly dry, with a solution of gelatino
or glue, water, spirits, perminent white or whitening, and glycerine, then, after
drying the plates completely, imprinting the same by means of a suitable printing
machine, coating the printed plates with colourless fac and drying them, substau-
tially as set forth.
Dated this 27th day of January 1891.