257 Grolleg Porcelain | High-fire White Clay | Cone 8-10 | Standard Clay | American Ceramic Supply Co.

A porcelain body with parian like quality. It's white, tight, and translucent when thin. Contains no ball clay.

Firing Temperature range : Cone 8-10

(2280–2345°F / 1249–1285°C)

This clay body is formulated for high-fire applications and performs optimally within the Cone 8 to Cone 10 range.

For slow firing schedules (typical in gas kilns or controlled oxidation/reduction firings), expect the following temperature benchmarks: For fast firing cycles—often used in electric kilns—the temperatures required to achieve each cone are slightly lower due to reduced heatwork over time:

Note: Electric kilns generally follow fast firing profiles, meaning actual peak temperatures may be up to 30°F (15–20°C) lower than traditional gas kiln firings. Always consider your kiln type and firing schedule when targeting a specific cone to ensure proper vitrification and glaze fit.

Cone 8 Average Shrinkage 13.5% Absorption 0.75%

Cone 10 Average Shrinkage 14.0% Absorption 0.5%

All clays come in 25 lb. bag - 2 bags per 50 lb. box.

Need firing advice or tips? No worries!
Reach out to Sales@americanceramic.com — ACS’s team of ceramic experts will be happy to help you. :)