ivor & olive lewis on sat 20 mar 10
When small quantities of material need to be reduced to an ultrafine powder
a pestle and mortar can be a useful tool to have on the bench.
I made several many years ago from a standard porcelain clay. On the larger
ones I left the interior unglazed. They are easy to clean. Efficient mullin=
comes from having the outer radius of the pestle just slightly less than th=
interior radius of the mortar and rocking the pestle forcefully on the
sample being crushed.