Item #: MBENMAC
Priced Per Pound
Macaloid is the trade name for an extremely fine-grained clay derived from volcanic materials. Macaloid is geologically and chemically similar to bentonite, but there are notable differences -- in particular, Macaloid contains a higher percentage of magnesium.
When used in glazes, Macaloid is a suspension agent. Additionally, Macaloid can increase the drying rate of water suspended glazes, which means that it can simply help applied glazes to dry a bit faster. Because Macaloid is quite similar to bentonite, this means that you can use it like bentonite -- add it to glazes in a small amount (1-2% of dry weight) for increased suspension.
Like bentonite, Macaloid can also be used as an additive in claybodies for increased plasticity. The recommended amount is 2%, no more than 3%. In particular, macaloid is a good plasticizer for white claybodies such as porcelain, since it fires to a very crisp white. Keep in mind that increasing your macaloid content in a claybody does contribute to greater shrinkage.