phenomenon is the reverse of crazing and is indicated by a very
low coefficient of thermal expansion for the unity formula of the
glaze and when the difference between the coefficient of expansion
for the glaze and that of the clay body is great.
the glaze ends up being "too big" for the clay body underneath.
these circumstances if the clay body is very thin and the glaze
very thick the clay body may crack (dunt) during cooling as it contracts
under the glaze.