e danger of
trying your eyes too much if you are not careful in this respect.

You must never continue the work if your eyes feel tired. Some person's
eyesight is so much stronger than that of others that you must judge for
yourselves whether or no it is harmful to you to produce such fine
paintings. It is best to sketch the portrait first correctly on paper;
not many amateurs will be able to do it direct on the ivory without some
guide, and as few alterations as possible must be made on the ivory. If
the sketch be tolerably dark it may be laid beneath the ivory, and so
traced off with a brush filled with light red. It is far easier, of
course, to work from a photograph; if you do this you need only to place
the ivory over it, and thus you have the features, and the principal
folds of the dress, ready to mark off with the brush on the
semi-transparent ground. You must be so very careful not to let the
ivory slip in the faintest degree out of place, or the likeness will
sure to prove a failure.

When you have all the principal points clearly defined, fix it by
gumming it at the top to a square of writing-paper, which must be white.
At the back of this lay three or four more squares of paper, until the
ivory thus mounted looks opaque. Bristol board is used sometimes instead
of paper, but it is liable to warp when exposed to heat. The ivory must
only be gummed at the top, for if gum were allowed to run under the face
the flesh-tints would be darkened; the papers also must be gummed
together at the top, and they should be somewhat larger than the ivory.
It must be placed aside until dry pressed in a book with a piece of
clean paper over it. Lay on the first flesh-tint evenly with a large
brush, leaving the whites of the eyes untouched. Light red, or Venetian
red, to which the slightest touch of yellow has been added, forms a good
tint to work upon; for dark complexion a little more yellow will be
requisite.

When the right depth of colour in the lights of the face is properly
secured, the shadows may be put in with a good-sized brush. It is a
great mistake ever to use very small brushes when larger ones can be
equally well employed. In every style of painting we should strive to
work as far as possible in a broad manner, and large brushes help us to
do this. So, too, we should whenever practicable lay on our colours in
washes; if we begin with stippling our drawings they will be "niggling,"
and will be sure to look poor