IMPROVEMENTS IN THE PREPARATION OF ZINC PLATES OR BLOCKS FOR PRINTING AND OTHER PURPOSES
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by John Henry Johnson at the Office
of the Commissioners of Patents on the 5th October 1882. Communicated
to him from abroad by Jules Adolph Silvestre of Paris in the Republic of
France.
JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleinan "IMPROVEMENTS IN THE PREPARATION OF ZINC PLATES OR BLOCKS
FOR PRINTING AND OTHER PURPOSES a communication to me from abroad by
Jules Adolphe Silvestre of Paris in the Republic of France
•
"
This Invention relates to improvements in the preparation of zinc plates or blocks
for printing gilding decorating and other purposes and it consists in plating or
covering the surface of such plates or blocks with a coating of nickel after the
design or drawing has been engraved on the said plates as hereinafter described.
By these means a degree of hardness and polish is imparted to the surface of the
zinc plates rendering them superior to those ordinarily employed and their white-
ness and lustre also enable them to be employed for a variety of ornamental
purposes such as decorations for furniture, caskets, jewelry, and the like.
The employment of zinc plates for etching by photographic and paneiconographic
processes by transfer presents serious disadvantages. In many cases it is impossible
to employ this metal in gilding it is too soft or yielding and in typography it is
objectionable on account of its coarseness which renders the lines harsh whilst the
number of copies that can be printed from one plate is relatively small
In line engraving it is absolutely impossible to use zinc its softness and porosity
rendering it incapable of taking the degree of polish that is essential in the mode
of printing necessary for this class of engraving
Attempts have been made to obviate these disadvantages by nickel plating the
zinc plates before engraving thereon but no practical success has been attained by
these means. The strong acid required to dissolve the nickel being liable to very
rapidly destroy the other parts of the work directly it worked through the thin
layer of nickel and come into contact with the zinc underneath the latter
According to this Invention however the desired result is attained by first
engraving the zinc plates or blocks by any suitable means and then nickel plating
the engraved plates or blocks thus imparting to the engraving the strength and
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hardness of the nickel which is deposited in a thin layer upon its surface. For this
purpose the finished stereotype or engraved zinc plate is immersed in a bath of
sulphate of nickel and thus caused to receive under the action of an electric current
a thin layer or coating of nickel deposited in a similar manner to the ordinary
electro gilding or silvering process. This nickel plating of the engraved zinc plates
may however be effected by any other known means. The plates must be allowed
to remain in the nickel bath for a sufficient time to enable a coating of nickel to
be deposited of such thickness as to offer the desired resistance but not so thick
as to impair the effect of the engraving. The zinc may be alloyed with a small
quantity of copper, tin, lead antimony or other metal
This invention enables nickel plated engraved zine plates to be produced giving
the same results as a copper plate at about one tenth of the cost of the latter
The beauty of the nickel plated plates or stereos obtained as hereinbefore
described renders them applicable to the decoration of fancy articles or cabinet
work such as ornamental boxes matchboxes and in the manufacture of buttons
brooches and other small articles which may be made very cheaply of zinc and be
provided with ornaments in relief or otherwise by any of the processes herein before
described These plates may also be used in decorating or producing designs or
ornaments upon leather woven fabrics cardboard papier maché and the like