IMPROVE- MENTS IN DECORATION OR ORNAMENTATION OF CHINA, EARTHENWARE, AND PORCELAIN
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by William Sutherland at the Office of
the Commissioners of Patents on the 7th July 1879.
WILLIAM SUTHERLAND, of Manchester, in the County of Lancaster.
"IMPROVE-
MENTS IN DECORATION OR ORNAMENTATION OF CHINA, EARTHENWARE, AND
PORCELAIN."
This Invention relates to the decoration of tiles, plaques, vases, cups, plates, or
other articles of china, earthenware, and porcelain, and consists principally of a new
application or modification of the well known process of etching to the glazed
surface or enamel on such articles.
The process of etching upon metals, glass, and other surfaces by means of acids
has been practised for ages, but the application of such process to the decoration or
ornamentation of china, earthenware, or porcelain is of a very recent .date and in
fact has not yet been reduced to a practical form. The process is exceedingly
simple in practice, but if the etching is performed by hand, highly skilled labor
must be employed and the work would be proportionately costly. Attempts have
therefore been made at various times to apply the process of transfer printing (as
practised in the potteries) to accomplish the end in view, but such attempts have
not hitherto been attended with success, the cause of failure being that the printing
has always been effected in a bituminous ink capable of resisting the action of the
acid. This ink must from its very nature be used hot as generally practised in
transfer printing onto china, the result being that the ink by repeated heating
becomes brittle and loses its cohesiveness, and when applied to the glazed surface of
the earthenware the impressions produced are not sharp, but are ragged at their
edges and full of pinholes, and when subjected to the action of the acid rough
ragged lines and altogether unsatisfactory work are produced. The first part of this
Invention consists in the use and application of a printing ink which is diametrically
opposite to that above referred to, and which is totally removed before the acid is
applied. In carrying my Invention into practical effect I employ a copper plate
upon which is engraved in the usual manner the required design, and from this
plate I take an impression in the usual manner practised in the potteries, and
transfer the same to the glazed surface of a tile, plaque, or other article, using a
greasy printing ink made with boiled linseed oil, train oil, neatsfoot oil, or other
suitable non-drying oil or grease added in order to prevent the printing ink from
drying.
The design being thus transferred in the greasy ink to the glazed surface of the
article to be ornamented, I immerse the same in a bath of shellac varnish patent
knotting (or other hard quick drying varnish) the former being preferred, and I
then allow the superfluous varnish to drain off the ware and put the same into
a convenient place to dry, after which I subinit the article to a heat of about 100
degrees (Fahrenheit) which hardens the varnish and at the same time softens the
D77

page_text: printing ink, which latter may then be wiped off the glazed surface of the article
without disturbing the varnish, leaving the lines of the engraving sharp and clear;
-or-if-the-printing ink does not wipe off clean at once, I use spirits of turpentine,
which while softening and washing off the printing ink will not affect the shellac
varnish, there being no affinity between the two. I now subject the article so
prepared to the action of hydrofluoric acid either in a bath or by the action of the
vapor of the same in the usual manner. When the acid has eaten away the glazed
surface to the depth required I immerse the article in a bath of caustic soda which
effectually removes the shellac varnish, after which it is well washed in water to
remove the soda
The article is then ready for applying the color to the background or into the
etched lines.
These colors may be of any required tint or tone, and without glaze or gloss, the
dead color forming an agreeable contrast to the glazed surface of the figures or other
parts of the design. The broad parts of the design which are eaten away may be
filled in with a pencil in the ordinary manner, but to fill in the fine lines of the figure
or ornament I paint the whole surface of the parts and then remove the superfluous
color with a wooden spatula or bevil-edged piece of wood or flat steel scraper, and
the article is then fired in the kiln to secure the color in the usual manner.
The etching and backgrounds may be sunk to various depths as required, the
figures or other ornaments being in low relief.
A second and valuable portion of my Invention relates to the production of etched
gold ornaments, which I effect in the following manner:-I form the etched
ornament by the process already described and when it is washed off and clean I
paint the figure or ornament all over with gold paint up to the outline and also
into the lines of the etching.
It is then fired in the kiln and burnished in the usual manner, the result being
that the glazed surface of the figure or ornament will be of the usual bright
burnished gold color, whilst the etched lines will remain of the same color as when
it comes out of the kiln (viz., a dead golden brown); the etched lines being below the
surface, the burnisher cannot of course touch the color in the lines and so they
remain dead and brown in color, and a very beautiful effect is thus produced, saving
an immense amount of labor and enabling the most elaborate gold ornaments to be
produced at a moderate cost. Another beautiful effect may be produced by my
improved process in the following manner :-
I take the white ware in the biscuit form and cover it with a soft glaze of pink
or other light or dark tint or color, or with an opal glaze. I print the design on
this glaze in the manner hereinbefore described, and eat away (by hydrofluoric acid)
all the parts required, such as background and so forth, leaving in low relief the
figures or other ornaments of the pink glaze or other color.
I then fill in the background of a suitable color and the etched lines of another
color suitably contrasting with the tinted glaze before described, thus producing
etched and tinted enamel or opal figures upon a colored ground.
This Invention may also be used to produce various other new and beautiful
effects on china, earthenware, and porcelain besides those above named, and which
to the best of my knowledge and belief have never heretofore been produced.