the original standard. All flax canvas is essentially of double warp,
for it is invariably intended to withstand some pressure or rough usage.

In structure it is similar to jute tarpaulin; indeed, if it were not for
the difference in the fibre, it would be difficult to say where one type
stopped and the other began. "Bagging," "tarpaulin" and "canvas" form an
ascending series of cloths so far as fineness is concerned, although the
finest tarpaulins are finer than some of the lower canvases. The cloth
may be natural colour, bleached or dyed, a very common colour being tan.
It has an enormous number of different uses other than naval.

Amongst other articles made from it are:--receptacles for photographic
and other apparatus; bags for fishing, shooting, golf and other sporting
implements; shoes for cricket and other games, and for yachting;
travelling cases and hold-alls, letter-bags, school-bags and nose-bags
for horses. Large quantities of the various makes of flax and cotton
canvases are tarred, and then used for covering goods on railways,
wharves, docks, etc.

Sail canvas is, naturally, of a strong build, and is quite different
from the canvas cloth used for embroidery purposes, often called "art
canvas." The latter is similar in structure to cheese cloths and
strainers, the chief difference being that the yarns for art canvas are,
in general, of a superior nature. All kinds of vegetable fibres are used
in their production, chief among which are cotton, flax and jute. The
yarns are almost invariably two or more ply, an arrangement which tends
to obtain a uniform thickness--a very desirable element in these
open-built fabrics.

[Illustration.]

The plain weave A in the figure is extensively used for these fabrics,
but in many cases special weaves are used which leave the open spaces
well defined. Thus weave B is often employed, while the "imitation
gauze" weaves, C and D, are also largely utilized in the production of
these embroidery cloths. Weave B is known as the hopsack, and probably
owes its name to being originally used for the making of bags for hops.
The cloth for this purpose is now called "hop pocketing," and is of a
structure between bagging and tarpaulin. Another class of canvas, single
warp termed "artists' canvas," is used, as its name implies, for
paintings in oils. It is also much lighter than sail canvas, but must,
of necessity, be made of level yarns. The best qualities are made of
cream or ble