various glazes are fired on samples of the same clay body in identical
firing conditions, the degree of crazing which results may vary.
Some, in fact, may not craze at all.
calculated coefficient of expansion for each of these glazes would
reflect the degree of crazing which eventuates.
one of these glazes is found to 'fit' the clay body on which it
was tested its coefficient of expansion should be noted.
value can then be used as a crazing benchmark when assessing
the tendency for other unfired glazes to craze if they were to be
fired on the same clay body under similar firing conditions.
clay body will have its own benchmark for crazing. A glaze which
crazes on one body may not craze on another.
must be emphasized that comparing glazes for their tendency to craze
only valid if those glazes were to be fired on the same clay
body to the same temperature with the same firing