Significance and Use The traditional method of preparing glazes
and slurries has been to add stains (pigments), stabilizers,
viscosity control agents, bactericides, and so forth, to the
pebble mill batch along with normal batch materials such as
clay, frit, quartz, feldspar, whiting (calcium carbonate), zinc
oxide, opacifier, and so forth. This method had the disadvantage
of over grinding some of the materials of the batch and under
grinding other materials. While part of the disadvantage could
be alleviated by double or triple batching (where the pebble
mill was stopped at one or two points in the cycle and one or
more materials added), the practice was labor intensive and not
always well controlled. Another disadvantage of the traditional
method was that it was necessary to thoroughly wash out the mill
between batches of different colors. An obvious advantage,
however, was that small components of the batch (such as
pigments) were thoroughly dispersed in the batch and even today
it is necessary to use this