imple cleaning purposes, or to efface the pencil lines when they
are drawn very lightly, squares of sponge-rubber answer admirably, these
being furnished by the dealers in drawing materials.

A piece of bread will answer a similar purpose, but it is less
convenient.

For glazed surface paper, as Bristol-board, the smoothest rubber must be
used, the grade termed velvet rubber answering well.

THE DRAWING PAPER.

Whatever kind of drawing paper be used it should be kept dry, or the
ink, however good it may be, will be apt to run and make a thick line
that will not have the sharp, clean edges necessary to make lines look
well.

Drawing paper is made in various qualities, kinds, and forms, as
follows: The sizes and names of paper made in sheets are:

Cap, 13 x 16 inches.
Demy, 20 x 15 "
Medium, 22 x 17 "
Royal, 24 x 19 "
Super Royal, 27 x 19 "
Imperial, 30 x 21 "
Elephant, 28 x 22 "
Columbier, 34 x 23 "
Atlas, 33 x 26 "
Theorem, 34 x 28 "
Double Elephant, 40 x 26 "
Antiquarian, 52 x 31 "
Emperor, 40 x 60 "
Uncle Sam, 48 x 120 "

the thickness of the sheets increasing with their size. Some sheets of
paper are hot pressed, to give a smoother surface, and thus enable
cleaner-edged lines to be drawn.

[Illustration: Fig. 13.]

For large drawings paper is made in rolls of various widths, but as
rolled paper is troublesome to lay flat upon the drawing board, it is
recommended to the learner to obtain the sheets, which may be laid
sufficiently flat by means of broad headed pins, such as shown in Figure
13, which are called thumb tacks. These are forced through the paper
into the board at each corner, as in Figure 14 at _f_. On account of the
large diameter of the stems of these thumb tacks, which unduly pierce
and damage the board, and on account also of their heads, by reason of
their thickness, coming in the way of the square blade, it will be
found preferable to use the smallest sizes of ordinary iron tacks, with
flat heads, whose stems are much finer and heads much thinner than thumb
tacks. The objection to ordinary tacks is that they are more difficult
to remove, but they are, as stated, more desirable for use.

[Illustration: Fig. 14.]

[Illustration: Fig. 15.]

If the paper is nearly the full size of the board, it does not