ghter and
lighter, bring it up in pitch with body color first, with solid
painting, and then glaze it.

Do not glaze on color which is not well dried. The drying of the under
color and the drying of the glaze are apt to be different in point of
time, and the picture will crack. If the vehicle is the same as was
used in the under-painting, and the drying qualities of both paintings
are the same, there is no danger. But when color dries, it shrinks and
flattens, and two kinds of colors shrinking differently are sure to
pull apart, and that causes cracking. If the under-painting is well
dry, but not hard and glossy on the surface, and is capable of still
absorbing enough of the new color's vehicle to bind the coats
together, your glaze will stand. But rather than have it too soft,
have the under-painting too hard, and then before you glaze go over it
with a little thin, quick-drying varnish, and glaze into that. The
varnish will hold the two coats of paint together.

Glazing, as well as scumbling, implies the obligation to varnish your
picture. Whenever you use oil freely you will have to varnish your
picture to keep it bright and fresh in color.

It would be wise never to use a glaze as a final process. Glaze to get
the tone or to modify it, but paint into the glaze with body color,
and you keep the advantage of the glaze without many of the
disadvantages of it, and the picture has a more solid effect of
painting.

=Frottee.=--Closely akin to the glaze in manner, but very different in
use, is the _frottee_, or "rubbing." This is generally used on the
fresh surface of the canvas, to "rub in" the light and shade or the
first coloring of the picture after the drawing is done. It is one of
the safest and wisest ways of beginning your picture. You can either
rub in the picture with a _frottee_ of one color, as sienna or umber,
or you can use all the colors in their proper places, only using very
little vehicle, and making something very thin in tint, somewhat
between a glaze and a scumble. You can make a complete drawing in
monochrome in this way, or you can lay in all the ground colors of the
picture till it has much the effect of a complete painting. Then, as
you paint and carry the picture forward, every color you put on will
be surrounded with approximately the true relations, instead of being
contrasted by a glare of white canvas.

A _frottee_ is a most sympathetic ground to paint over.