The WORKABILITY of a clay must be such that it can be formed into
the required shape without cracking or sagging; at this point it is
necessary to add "BY A GOOD TECHNICIAN", we are judging clays,
not potters. Different standards of workability are required for
throwing bodies, hand-building bodies, those meant for tiles, etc.

PLASTICITY is the major factor of workability, it has never been
adequately described but it has to do with the ability of a clay to be
deformed and then hold the new shape. This has nothing to do with
smoothness; kaolin is very low in plasticity and is quite flabby in the
green state, ball clay is very plastic and quite firm in the green
state, both are very smooth to the touch. With high plasticity goes
exceptional workability, high green strength and drying problems,
with low plasticity goes a narrow range of workability, low green
strength and trouble-free drying; plasticity should be modulated to
fit the job at hand.

DRYING CHARACTERISTICS involve the least understood proper-
ties of clays, this subject will be dealt with fully in the next paper of
this series. Pieces of moderate size should not crack for the
experienced potter, if they do it means that the body has too great

a drying shrinkage for the job, or is too dense to permit the easy
passage of water from one part of the piece to another, or the body
is too low in green strength to permit even moderate strains in
drying. Frequently the drying problems encountered are not due

to the drying characteristics of the clay but rather to the drying
procedures employed.

The GREEN STRENGTH of a body should be great enough to permit
reasonable handling of ware during drying and stacking after dry-

ing. It shouldn't be assumed that all potters handle their ware
reasonably, many don't, With experience one can learn to distinguish

between handling and drying cracks.

TEXTURE of a clay is important to workability, drying and final
appearance, of these good drying properties of coarse textured
bodies is probably the most significant.

6.