Handbook on Japanning: 2nd Edition | Page 4

which must be made to boil gently when
the gum is put into it. After being diluted with turps the white ground
may be applied in this varnish, and then a coat or two of the varnish
itself may be applied over it. These coats, however, take a long time to
dry, and, owing to its softer nature, this japanned surface is more
readily injured than that yielded by the shellac varnish.
According to Mr. Dickson, "the old way of making a cream enamel for
stoving (a white was supposed to be impossible) was to mix ordinary
tub white lead with the polishing copal varnish and to add a modicum
of blue to neutralize the yellow tinge, stove same in about 170°F. and
then polish as before described". "This," continues Mr. Dickson,
"would at the best produce but a very pale blue enamel or a cream. It
was afterwards made with flake white or dry white lead ground in turps
only and mixed with the polishing copal varnish with the addition of
tints as required, by which means a white of any required character
could be produced."

BLUE JAPAN GROUNDS.
Authorities state that these may be formed from bright Prussian blue or
verditer glazed over with Prussian blue or of smalt. By bright Prussian
blue possibly a genuine Prussian blue toned down to a sky blue with
white lead is meant, and by verditer the variety known as refiners' blue
verditer, and as to smalt it must not be forgotten that it changes its
colour in artificial light. Be that as it may, the pigment may be mixed
with the shellac varnish according to the instructions already given, but
as the shellac will somewhat injure the tone of the pigment by
imparting a yellow tinge to it where a bright true blue is required, the
directions already given as regards white grounds must be carried out.
SCARLET JAPAN GROUND.
Vermilion is the best pigment to use for a scarlet japan ground, and its
effect will be greatly enhanced by glazing it over with carmine or fine
lake. If, however, the highest degree of brightness be required the white
varnish must be used. Vermilion must be stoved at a very gentle heat.
RED JAPAN GROUND.
The basis of this japan ground is made up with madder lake ground in
oil of turpentine, this constitutes the first ground; when this is perfectly
dry a second coat of lake and white in copal varnish is applied, and the
last coat is made up of lake in a mixture of copal varnish and turpentine
varnish.
BRIGHT PALE YELLOW GROUNDS.
Orpiment or King's yellow may be used, and the effect is enhanced by
dissolving powdered turmeric root in the methylated spirits from which
the upper or polishing coat is made, which methylated spirits must be
strained from off the dregs before the seed-lac is added to it to form the
varnish. The seed-lac varnish is not so injurious to yellow pigments as
it is to the tone of some other pigments, because, being tinged a reddish
yellow, it does little more than intensify or deepen the tone of the
pigment.
GREEN JAPAN GROUNDS.
Green japan grounds are produced by mixing Prussian blue or distilled
verdigris with orpiment, and the effect is said to be extremely brilliant
by applying them on a ground of leaf gold. Any of them may be used
with good seed-lac varnish, for reasons already given. Equal parts by
weight of rosin, precipitated rosinate of copper, and coal-tar solvent

naphtha will give a varnish which, when suitably thinned and the coats
stoved at a heat below 212° F., will give a green japan second to none
as a finishing coat as regards purity of tone at least. To harden it and
render it more elastic half of the rosin might be replaced by equal
weights of a copal soluble in solvent naphtha and boiled linseed oil, so
that the mixture would stand thus: rosinate of copper 1 lb., rosin 1/2 lb.,
boiled oil 1/4 lb., hard resin (copal) 1/4 lb., solvent naphtha 1 lb. When
heated to a high temperature this rosinate of copper varnish yields a
magnificent ruby bronze coloration, especially on glass. Verdigris
dissolves in turpentine, and successful attempts might be made to make
a green japan varnish from it on the lines indicated for rosinate of
copper.
ORANGE-COLOURED GROUNDS.
Orange-coloured grounds may be formed by mixing vermilion or red
lead with King's yellow, or orange lake or red orpiment (? realgar) will
make a brighter orange ground than can be produced by any mixture.
PURPLE GROUNDS.
Purple grounds may be produced by the admixture of lake or vermilion
with Prussian blue. They may be treated as the other coloured grounds
as regards the varnish vehicle.
BLACK GROUNDS.
Black grounds may be