Slip Casting & Pottery Plaster Calculators

Casting slip can share the same specific gravity and still behave differently because viscosity and thixotropy also matter. Treat the values here as one part of a repeatable studio check: weigh a known volume, time a flow test, and record the mold condition.

For plaster, the manufacturer's water-to-plaster ratio takes priority over a generic preset. Weigh both materials; do not measure plaster by volume. A consistent ratio is what makes mold strength and absorption comparable from one mix to the next.