Made primarily of English Grolleg. Contains plasticizers to make this the finest translucent porcelain available for throwing, thin slab work and handbuilding. The "standard" porcelain for the US Northeastern potters. 

Reduction fired in first image and oxidation in the second image.

Characteristics:
Cone: 10 
Wet Color: White 
Firing Color: Reduction: Gray/White 
Texture: Smooth 
Consistency: Slightly Firm 
Avg. Shrinkage ±2%: 14.75% 
Avg. Water Absorption ±1%: 0.3% 
COE x 10-6: 5.46