al liking. It would be well to
consider what the effect of the ground will be on the future condition
of the picture when the colors begin to effect each other, as they
inevitably will sooner or later.

Vibert in his "_La Science de la Peinture_" advocates a white ground.
He says that as the color will be sure to darken somewhat with time,
it is well that the ground should have as little to do with it as
possible. If the ground is white there is so much the less dark
pigment to influence your painting. He is right in this; but white is
a most unsympathetic color to work over, and if you do not want to lay
in your work with _frottees_, a tint is pleasanter. For most work the
light ochrish ground will be found best; but you may be helped in
deciding by the general tone of your picture. If the picture is to be
bright and lively, use a light canvas, and if it is to be sombre, use
a dark one. Remember, too, that the color of your ground will
influence the appearance of every touch of paint you put on it by
contrast, until the priming is covered and out of sight.

=Stretchers.=--The keyed stretcher, with wedges to force the corners
open and so tighten the canvas when necessary, is the only proper one
to use. For convenience of use many kinds have been invented, but you
will find the one here illustrated the best for general purposes. The
sides may be used for ends, and _vice versa_. If you arrange your
sizes well, you will have the sides of one size the right length for
the ends of another. Then you need fewer sizes, and they are surer to
pack evenly.

[Illustration: =Stretchers.=]

=Stretching.=--You will often have to stretch your own canvases, so
you should know how to do it. There is only one way to make the canvas
lay smoothly without wrinkles: Cut the canvas about two inches longer
and wider than the stretcher, so that it will easily turn down over
the edges. Begin by putting in _one tack_ to hold the _middle_ of one
end. Then turn the whole thing round, and stretch tightly lengthwise,
and put a tack to hold it into the _middle_ of the other end. Do the
same way with the two sides. Only four tacks so far, which have
stretched the canvas in the middle two ways. As you do this, you must
see that the canvas is on square. Don't drive the tacks all the way in
at first till you know that this is so. Then give each another blow,
so that the head binds the canvas more than the body of the tack does;
for the pull of the can