JAPAN GROUNDS.
The japan ground properly so called consists of the varnish and
pigment where the whole surface is to be of one simple colour, or of
the varnish, with or without pigment, on which some painting or other
form of decoration is afterwards to be applied. It is best to form
this ground with the desired pigment incorporated with shellac
varnish, except in the case of a white japan ground which requires
special treatment, or when great brilliancy is a desideratum and other
methods must be adopted. The shellac varnish for the japan ground is
best prepared as follows: shellac 1-1/4 lb., methylated spirits 1
gallon. Dissolve in a well-corked vessel in a warm place and with
frequent shaking. After two or three days the shellac will be
dissolved. It is then recommended to filter the solution through a
flannel bag, and when all that will come through freely has done so
the varnish should be run into a proper sized vessel and kept
carefully corked for use. The bag may then be squeezed with the hand
till the remainder of the fluid varnish is forced through it, and this
if fairly clear may be used for rough purposes or added to the next
batch. Pigments of any nature whatever may be used with the shellac
varnish to give the desired tint to the ground, and where necessary
they may be mixed together to form any compound colour, such as blue
and yellow to form green. The pigments used for japan grounds should
all be previously ground very smooth in spirits of turpentine, so
smooth that the paste does not grate between the two thumb nails, and
then only are they mixed with the varnish. This mixture of pigment and
varnish vehicle should then be spread over the surface to be japanned
very carefully and very evenly with a camel-hair brush. As metals do
not require a priming coat of size and whiting, the japan ground may
be applied to metallic surfaces forthwith without any preliminary
treatment except thorough cleansing, except in the cases specially
referred to further on. On metallic surfaces three to four coats are
applied, and in the interval between each coat the articles must be
stoved in an oven heated to from 250° to 300° F.
WHITE JAPAN GROUNDS.
The formation of a perfectly white japan ground and of the first
degree of hardness has always been difficult to attain in the art of
japanning, as there are few or no substances that can be so dissolved
as to form a very hard varnish coat without being so darkened in the
process as to quite degrade or spoil the whiteness of the colour. The
following process, however, is said to give a composition which yields
a very near approach to a perfect white ground: Take flake white or
white lead washed and ground up with the sixth of its weight of starch
and then dried, temper it properly for spreading with mastic varnish
made thus: Take 5 oz. of mastic in powder and put it into a proper
vessel with 1 lb. of spirits of turpentine; let them boil at a gentle
heat till the mastic be dissolved, and, if there appear to be any
turbidity, strain off the solution through flannel. Apply this
intimate and homogeneous mixture on the body to be japanned, the
surface of which has been suitably prepared either with or without the
priming, then varnish it over with five or six coats of the following
varnish: Provide any quantity of the best seed-lac and pick out of it
all the clearest and whitest grains, take of this seed-lac 1/2 lb. and
of gum anime 3/4 lb., pulverize the mixture to a coarse powder and
dissolve in a gallon of methylated spirits and strain off the clear
varnish. The seed-lac will give a slight tint to this varnish, but it
cannot be omitted where the japanned surface must be hard, though
where a softer surface will serve the purpose the proportion of
seed-lac may be diminished and a little turpentine oleo-resin added to
the gum anime to take off the brittleness. A very good varnish
entirely free from brittleness may, it is said, be formed by
dissolving gum anime in old nut or poppy oil, 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 formed either from lamp black or ivory black, but
ivory black is preferable to lamp black, and possibly carbon black or
gas black to either. These may be always applied with the shellac
varnish as a vehicle, and their upper or polishing coats may consist
of common seed-lac varnish. But the best quality of ivory black ground
in the best super black japan yields, after suitable stoving, a very
excellent black indeed, the purity of tone of which may be improved by
adding a little blue in the grinding.
COMMON BLACK JAPAN GROUNDS ON METAL.
Common black japan grounds on metal by means of heat are procured in
the following manner: The surface to be japanned must be coated over
with drying oil, and when it is moderately dry must be put into a
stove of such heat as will change the oil black without burning it.
The stove should not be too hot when the oil is put into it nor the
heat increased too fast, either which error would make it blister, but
the slower the heat is increased and the longer it is continued,
provided it be restrained within a due degree, the harder will be the
coat of japan. This kind of japan requires no polish, having received
from the heat, when properly regulated, a sufficiently bright surface.
TORTOISE-SHELL GROUND.
This beautiful ground, produced by heat, is valued not only for its
hardness and its capacity to stand a heat greater than that of boiling
water, but also for its fine appearance. It is made by means of a
varnish prepared thus: Take one gallon of good linseed oil and half a
pound of umber, boil them together until the oil becomes very brown
and thick, strain it then through a coarse cloth and set it again to
boil, in which state it must be continued until it acquires a
consistency resembling that of pitch; it will then be fit for use.
Having thus prepared the varnish, clean well the surface which is to
be japanned; then apply vermilion ground in shellac varnish or with
drying oil, very thinly diluted with oil of turpentine, on the places
intended to imitate the more transparent parts of the tortoise-shell.
When the vermilion is dry, brush the whole over with the black varnish
thinned to the right consistency with oil of turpentine. When set and
firm put the work into a stove where it may undergo a very strong
heat, which must be continued a considerable time, for three weeks or
even a month so much the better. This ground may be decorated with
painting and gilding in the same way as any other varnished surface,
which had best be done after the ground has been hardened, but it is
well to give a second annealing at a very gentle heat after it has
been finished. A very good black japan may be made by mixing a little
japan gold size with ivory or lamp-black, this will develop a good
gloss without requiring to be varnished afterwards.
PAINTING JAPAN WORK.
Japan work should be painted with real "enamel paints," that is with
paints actually ground in varnish, and in that case all pigments may
be used and the peculiar disadvantages, which attend several pigments
with respect to oil or water, cease with this class of vehicle, for
they are secured by it when properly handled from the least danger of
changing or fading. The preparation of pigments for this purpose
consists in bringing them to a due state of fineness by grinding them
on a stone with turpentine. The best varnish for binding and
preserving the pigments is shellac. This, when judiciously handled,
gives such a firmness and hardness to the work that, if it be
afterwards further secured with a moderately thick coat of seed-lac
varnish, it will be almost as hard and durable as glass. The method of
painting in varnish is, however, far more tedious than with an oil or
water vehicle. It is, therefore, now very usual in japan work for the
sake of dispatch, and in some cases in order to be able to use the
pencil (brush) more freely, to apply the colours in an oil vehicle
well diluted with turps. This oil (or japanners' gold size) may be
made thus: Take 1 lb. of linseed oil and 4 oz. of gum anime, set the
oil in a proper vessel and then add the gum anime powder, stirring it
well until the whole is mixed with the oil. Let the mixture continue
to boil until it appears of a thick consistence, then strain the whole
through a coarse cloth and keep it for use. The pigments are also
sometimes applied in a gum-water vehicle, but work so done, it has
been urged, is not nearly so durable as that done in varnish or oil.
However, those who formerly condemned the practice of japanning
water-coloured decorations allowed that amateurs, who practised
japanning for their amusement only and thus might not find it
convenient to stock the necessary preparations for the other methods,
might paint with water-colours. If the pigments are ground in an
aqueous vehicle of strong isinglass size and honey instead of gum
water the work would not be much inferior to that executed with other
vehicles. Water-colours are sometimes applied on a ground of gold
after the style of other paintings, and sometimes so as to produce an
embossed effect. The pigments in this style of painting are ground in
a vehicle of isinglass size corrected with honey or sugar-candy. The
body with which the embossed work is raised is best formed of strong
gum water thickened to a proper consistency with armenian bole and
whiting in equal parts, which, being laid on in the proper figures and
repaired when dry, may be then painted with the intended pigments in
the vehicle of isinglass size or in the general manner with shellac
varnish. As to the comparative value of pigments ground in water and
ground in oil, that is between oil-colours and water-colours in
enamelling and japanning, there seems to have been a change of opinion
for some time back, especially as regards the enamelling of slate. The
marbling of slate (to be enamelled) in water-colours is a process
which Mr. Dickson says well repays study. It is greatly developed in
France and Germany. The process is a quick one and the pigments are
said to stand well and to maintain their pristine hue, yet if many
strikingly natural effects result from the use of this process, its
use has not spread in Great Britain, being confined wholly and solely
to the marbling of slate (except in the case of wall-paper which is
water-marbled in a somewhat similar way).
"In painting in oil-colour," says Mr. Dickson, "the craftsman trusts
largely to his badger-hair brush to produce his effects of softness
and marbly appearance; but in painting in water-colours, this
softness, depth, and marbly appearance are produced mostly by the
colour placed upon the surface, and left entirely untouched by badger
or any other brush. The colour drying quickly, does not allow much
time for working, and when dry it cannot be touched without spoiling
the whole of the work. The difference first of all between painting in
water and in oil colour, is that a peculiar grain exists with painting
in water that it is absolutely impossible to get in oil. The charm of
a marble is, I think, its translucency as much as its beautiful
colour; it is to that translucency (for in marble fixed we have no
transparency) that it owes its softness of effect, which makes marble
of such decorative value. This translucency can only be obtained by
thin glazes of colour, by which means each succeeding glaze only
partly covers the previous one, the character of the marble being thus
produced. This is done sometimes in oil-colour in a marvellous manner,
but even the best of oil-painting in marble cannot stand the
comparison of water-colour, and it is only by comparison that any
accurate judgment can be formed of any work. The production of marbles
in water-colour has a depth, softness, and stoniness that defies
oil-painting, and in some cases will defy detection unless by an
expert of marbles. It may be that first of all the materials employed
are more in keeping with the real material, as no oil enters into the
composition of real marble, and by using the medium of water we thus
start better, but the real secret is that by using water as a medium
the colours take an entirely different effect. In painting in
water-colour greys of any tint or strength can be obtained suitable
for the production of a marble of greyish ground, by pure white,
tinted as required, being applied of different thicknesses of colour,
all the modulations of tone being obtained by the difference in the
thickness of the colour applied."
VARNISHING JAPAN WORK.
Varnishing is the last and the finishing process in japanning. It
consists in (1) applying, and (2) polishing the outer coats of
varnish, which are equally necessary whether the plain japan ground be
painted on or not. This is best done in a general way with common
seed-lac varnish, except on those occasions where other methods have
been shown to be more expedient, and the same reasons, which decide as
to the propriety of using the different varnishes as regards the
colours of the ground, hold equally with those of the painting, for
where brightness is a material point and a tinge of yellow would
injure it, seed-lac must give way to the whiter resins; but where
hardness and tenacity are essential it must be adhered to, and where
both are necessary a mixed varnish must be used. This mixed varnish
should be made from the picked seed-lac as directed in the case of the
white japan grounds. The common seed-lac varnish may be made thus:
Take 1-1/2 lb. of seed-lac and wash it well in several waters, then
dry it and powder it coarsely and put it with a gallon of methylated
spirits into a Bohemian glass flask so that it be not more than
two-thirds full. Shake the mixture well together and place the flask
in a gentle heat till the seed-lac appears to be dissolved, the
shaking being in the meantime repeated as often as may be convenient;
then pour off all the clear and strain the remainder through a coarse
cloth. The varnish so prepared must be kept for use in a well-corked
glass vessel. The whiter seed-lac varnishes are used in the same
manner as the common, except as regards the substances used in
polishing, which, where a pure white or the greater clearness or
purity of other pigments is in question, should be itself white, while
the browner sorts of polishing dust, as being cheaper and doing their
business with greater dispatch, may be used in other cases. The pieces
of work to be varnished should be placed near the fire or in a warm
room and made perfectly dry, and then the varnish may be applied with
a flat camel-hair brush made for the purpose. This must be done very
rapidly, but with great care; the same place should not be passed
twice over in laying on one coat if it can possibly be avoided. The
best way of proceeding is to begin in the middle and pass the brush to
one end, then with another stroke from the middle pass it to the other
end, taking care that before each stroke the brush be well supplied
with varnish; when one coat is dry another must be laid over it in
like manner, and this must be continued five or six times. If on trial
there be not a sufficient thickness of varnish to bear the polish
without laying bare the painting or ground colour underneath more
varnish must be applied. When a sufficient number of coats of varnish
is so applied the work is fit to be polished, which must be done in
common work by rubbing it with a piece of cloth or felt dipped in
tripoli or finely ground pumice-stone. But towards the end of the
rubbing a little oil of any kind must be used with the powder, and
when the work appears sufficiently bright and glossy it should be
well rubbed with the oil alone to clean it from the powder and to give
it a still greater lustre. In the case of white grounds, instead of
the tripoli, fine putty or whiting should be used, but they should be
washed over to prevent the danger of damaging the work from any sand
or any other gritty matter that may happen to be mixed with them. It
greatly improves all kinds of japan work to harden the varnish by
means of heat, which, in every degree that can be applied short of
what would burn or calcine the matter, tends to give it a firm and
strong texture where metals form the body; therefore a very hot stove
may be used, and the stoving may be continued for a considerable time,
especially if the heat be gradually increased. But where wood or
papier-mâché is in question, heat must be applied with great caution.