Optikast Kaolin

Optikast is a kaolin with rather unusual properties.

• Very low plasticity
  • When mixed into a slip and dried, it flakes apart
  • Needs very little water to suspend (relative to other kaolins)
  • Does not appear to increase plasticity in clay bodies
• High silt content
  • According to Digital Fire, 45% of Optikast particles are larger than 2 microns (the approximate cutoff for clay particle size)

I wonder if Optikast is created from the same mine as Tile 6 Kaolin - they have very similar chemical analyses, even down to the iron and titanium contamination.

Optikast's low plasticity means it can be substituted for calcined kaolin in recipes. I've used it successfully in glazes and in wadding. However, it may not be economical to keep on hand.

Created 2024-04-18. Updated 2024-07-01.

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