Bentonite 325 is the most commonly used bentonite, and it is considered a standard glaze and clay additive.
At times it can be coarser than 325 mesh, and it may cause some specking if used in amounts over 1%.
Bentonite clay is used to thicken lotions, emulsify oils and help hydrate skin.
It is commonly added to shaving soap to make the razor less likely to cut the skin.
Bentonite clay also has the ability to absorb toxins and poisons, heavy metals, and other impurities and contaminants, and then keep them contained in the center of the clay.
When added to soap, it will help the soap clean oily skin and add slip to the soap. Use about 1/8 cup for every 4-lb batch for best results.
Always add bentonite to dry compositions, as the bentonite will swell in water.
Excessive bentonite in a glaze will make it become gel-like.