charcoal, which could be
signed and framed. This is then "fixed" by a spray of alcohol and gum
shellac, thrown by means of a common perfume atomizer, the whole
apparatus costing less than one American dollar.

On this I begin my color scheme in both opaque and transparent color,
recognizing the "natural facts" already explained to you, that is, the
skies and high lights being solidly opaque, the shadows being equally
transparent. This process requires certain modifications to be made in
the darks of the original drawing. The dense black shadow under the
eaves of a roof, for instance, are not in nature as black as the
charcoal, but perhaps a rich, warm brown. If the ground is in
sunlight, it is a dull, golden yellow and reflects the yellow glow of
the sand beneath. Or it may be a blue reflection, or even of a reddish
tone. These hard blacks then must be _glazed_ in such a way as to
preserve the power of the shadow obtained by means of the under
charcoal, and yet keep it _transparent_ (all shadows being
transparent) and at the same time preserve its true and proper tint.

This glaze is done by using the three semi-opaque primary
pigments--found in every color-box--namely:

Light red,

Cobalt-blue,

Yellow ochre.

These colors, of course, form the basis of all intermediate tones, and
from them all intermediate tones can be made.

These three colors are at the same time semi-opaque, their opacity
being just sufficient to tint the hard black of the coal, while never
clogging or muddying its transparency.

So it is with the millions of other tones in the whole composition,
when such perfectly transparent colors as brown madder, Indian yellow,
and indigo are used as a glaze, altering and modifying the undertone
of charcoal to any desired tint and at the same time preserving the
all-important thing--its transparency.

In conclusion, let me say that I fully recognize that I am addressing
students whose training enables them to understand perfectly this
explanation, and that further instructions are therefore unnecessary.

One thing, however, may be accentuated, and that is the use of plenty
of clean water. Another is that you should keep your palettes
separate. For myself, I make use of a common white metallic
dinner-plate, known as iron-stone china, costing another ten cents,
for my sky-palette, squeezing the color-tubes in a row around its edge
and my Chinese white below them on one side toward the bottom. For my