Studio: international art (3.1894)

On Gesso

substance of the relief should be retained during
the execution of the painting. Do not indif-
ferently lose this natural white ground for the
sake of replacing by any substituted white paint.
If you are forced to resort to an overlaid white,
use zinc white in wax in preference to flake white.
Thin zinc white will not darken like thin flake
white, and is the less likely to be injured under
heat in the wax method. The finished work may
then have a final varnishing of wax, again made to
flow by slightly heating. When perfectly dry it
will bear polishing with a soft silk rag.

Oil paint darkens under most conditions ; on a
relief it becomes opaque and heavy. The paint
should always be thin and flooded on. Thick
paint would be more likely to peel off, and to show
a texture of the brush strokes. It is well to re-
member that paint is used here not in the painter's
sense, to paint with, but merely to find colour.
In ordinary descriptive painting, texture may be a
desideratum ; but on a relief is always in doubtful
taste, and of doubtful value. As a rough rule,
one might say never stroke the colour on, but
rather dab it or pat it on, with the brush held
perpendicularly to the relief. Where it is neces-
sary to use opaque colour, it should be em-
ployed almost as if it were metal, or used in
spots of colour, with the effect of precious
stones. Since thinness of paint combined with
covering capacity is to be desired, there is
sometimes an advantage in laying on opaque
colours in tempera. Work begun in tempera can
of course be finished in oil; a method which
was probably that of the earliest oil-painting.

For association with actual metal, oil is admirably
fitted. It especially lends itself to an enrichment
which is secured by dragging powder gold across
the high projections of the relief. If a whole
surface be gilded, beautiful effects can be obtained
by rubbing colour down into the hollows and
wiping it off from the ridges with a soft rag tightly
wrapped round the finger-tip. The rag should be
perpetually shifted in order to offer always a clean
surface to the paint. If it be required to wipe it
off still more sharply, use a little benzine ; dipping
the rag (still round the finger) into it. This will
fetch off some of the gold ; but delicate retouching
will be easy, if you apply a little powder gold with
the end of a brush ; the powder gold can be mixed
with the oil medium on the palette. Copal medium
answers very well. A long flat brush is best for
dragging the gold, which should be used rather
dry, trying in fact to secure a touch which is at
once full of intention and yet admits of the charm
158

of accident. The common bronze powders last
very well if protected from the air by a coat of
varnish; but real gold is so comparatively in-
expensive that it is wise to use it for work of any
importance. To lay on gold-leaf is an art well
worth acquiring, and, after two or three failures,
will be found byno means impossible,given patience
and care. You will not keep to your contours
at first, but the trade-gilder will never know the
edge you intended to keep. The amateur gilder is
sometimes much helped by using transfer gold-leaf;
the metal is attached to tissue-paper, which, how-
ever, it readily leaves to adhere to the sized ground.
It can be handled, and cut neatly to the required
shape with scissors. Naturally you will do all leaf
gilding before you begin colouring. Silver must
always be locked up from the air under a coat of
varnish. Aluminium is a safer substitute, although
its heaviness of colour is sometimes a disadvantage.
One may see the danger of using silver in the long
panel painting by Fra Angelico in the National
Gallery, where the trumpets have turned black.
It is wise to have a separate palette for all gold-
work, and for gold and all metals it is well to
insist that all appliances should be kept scru-
pulously clean.

Oil or wax will admit of your washing the relief
with soft sponge and clean warm water during the
execution of the painting. A moistened finger
will take away fine dust off dry paint; but dusting
or brushing it always rubs a little of the dust in, thus
permanently soiling the surface. Make a resolution
never to paint over a hair, or a grain of dust, but
always to stop and pick it off with the scraper. It
is not idle to insist on this precaution j nothing so
fatally cloys, sullies, and coarsens such work as we
are considering. The surface, if rightly laid on, is
quite textureless, and therefore the dust is much
more apparent than it would be in a picture where
a feeling for textures is the life of manipulation.

Metal is always valuable in colouring a relief,
because it forces you to avoid realistic treatment.
It should be used as colour rather than as repre-
senting metallic objects. You will find valuable
suggestions for its treatment in early Italian work.
Gilding is especially good. Gold is preferable to
white metal, for the background, which you cannot
then treat naturalistically as landscape. Severity,
simplicity, convention must be observed in the
colouring no less than in the modelling of objects
in a relief. Where the background is plain, it is
well to burnish the gold ; when the gold should be
laid upon a slightly undulating uneven surface,
roughened with brush stroke, to give greater play