and prevents tempting and specious tricks.

_How to Make a "Cut-line."_--But now, all this being granted, how are we
to set about getting the pieces cut? First of all, I would say that it
is always well to draw most, if not all, of the necessary lead lines on
the cartoon itself. By the necessary lead lines I mean those which
separate different colours; for you know that there _must_ be a
lead line between these. Then, when these are drawn, it is a question of
convenience whether to draw in also the more or less optional lead lines
which break up each space of uniform colour into convenient-sized
pieces. If you do not want your cartoon afterwards for any other purpose
you may as well do so: that is, first "set" the cartoon if it is in
charcoal or chalk, and then try the places for these lead lines lightly
in charcoal over the drawing: working thus, you can dust them away time
after time till they seem right to you, and then either set them also or
not as you choose.

A good, useful setting-mixture for large quantities is composed by
mixing equal parts of "white polish" and methylated spirit; allowing it
to settle for a week, and pouring off all that is clear. It is used in
the ordinary way with a spray diffuser, and will keep for any length of
time.

The next step is to make what is called the cut-line. To do this, pin a
piece of tracing-cloth over the whole cartoon; this can be got from any
artist's-colourman or large stationer. Pin it over the cartoon with the
dull surface outwards, and with a soft piece of charcoal draw lines 1/16
to 1/8 of an inch wide down the centre of all the lead lines: remove the
cloth from the cartoon, and if any of the lines look awkward or ugly,
now that you see them by themselves undisguised by the drawing below,
alter them, and then, finally, with a long, thin brush paint them in,
over the charcoal, with water-colour lamp-black, this time a true
sixteenth of an inch wide. Don't dust the charcoal off first, it makes
the paint cling much better to the shiny cloth.

When this is done, there is a choice of three ways for cutting the
glass. One is to make shaped pieces of cartridge-paper as patterns to
cut each bit of glass by; another is to place the bits of glass, one by
one, over the cut-line and cut freehand by the line you see through the
glass. This latter process needs no description, but you cannot employ
it for dark glasses because you cannot see the line through: for this
you must