ffectual, or it may be flipped into
its place, or it may be hatched on with parallel strokes. All these
ways will be spoken of as they suggest themselves in other chapters.
Solid color, generally, is used in this manner, and the effect of body
is rather strengthened by it than the reverse.

=Scumbling.=--Another means of modifying the color and effect of a
painting has perhaps always been more or less commonly in use. This is
called _scumbling_, and may be considered under the head of solid
painting, as it is always done with body, and never with transparent,
color. The process consists of rubbing a mixture of body color,
without thinning, over a surface previously painted and dried.
Generally this _scumble_ is of a lighter color than the
under-painting, and is rubbed on with a stubby brush slightly charged
with the paint. As much surface as is desired may be covered in this
way, and the result is to give a hazy effect to that part, and to
reduce any sharpness of color or of drawing. Often the effect is very
successfully obtained. Distant effects may be painted solidly and
rather frankly, and then brought into a general indefiniteness by
scumbling. Too much scumbling will make a picture vague and soft, and
after a scumble it is best to paint into it with firm color to avoid
this.

The scumble may be used with the richer and darker colors, too, to
modify towards richness the tone of parts of the picture, or to darken
the value. Most often, however, its value lies in its use to bring
harsher and sharper parts together, and to give the hazy effect when
it is needed.

Scumbling will not have a good effect when it is not intended to
varnish the picture afterwards; for the oil in the paint is absorbed
immediately, and the rubbing of color gives a dead look to the canvas
which is very unpleasant, and decidedly the reverse of artistic.

=Glazing.=--A very valuable process, the reverse of scumbling, is
glazing. It has always been in use since the invention of the oil
medium. All the Italian painters used it; it is an essential part of
their system of coloring. The rich, deep color of Titian, the warm
flesh of Raphael, and the jewel-like quality of the early German
painters are impossible without some form of glaze. The Germans
perhaps made glazes with white of egg before oil was used as a
vehicle. But to glaze is the only way to get the fullest effect of the
quality characteristic of the transparent paints.

A glaze is a