Amaco Kiln Ice

What are Kiln Ice Glazes? These glazes are modeled after Guan Ware - a type of Chinese ceramics that was produced during the Southern Song dynasty. 
How does the crackle happen? The crackle is caused by the expansion and contraction of the glaze and clay body in relation to one another also known as the CTE, Coefficient of thermal expansion. Glaze thickness can affect the size of the crackle, smaller and tighter when thin, larger, and hexagonal when thick. With this glaze thicker is better.
Recommended Clays: Brown or buff clays that do not contain manganese work best with these glazes. 
Application Tips: Apply Kiln Ice glazes thicker than traditional Amaco glazes, at least an 1/8 inch thick (3.175mm). Glaze thickness is critical to achieve a nice crackle. Multiple brushed on layers is better than one thick one. When the glaze thickness starts to get heavy it will take longer to dry in between coats, this is due to the gums that are added to make it brushable also slows the dry time when glaze is thick.
Food Safe? Yes, but due to durability, these glazes are not recommended for food surfaces. Use a liner glaze for any food surfaces on functional 
wares.
What determines the size and distribution of the crackles?
Glaze thickness can affect the size of the crackle, smaller and tighter when thin, larger, and hexagonal when thick. The clay body used will also affect the crackle. 

The crackle effect created with Kiln Ice glazes is achieved by intentionally creating a mismatch in thermal expansion between the glaze and the clay body. Because of this, they are under high tension. To prevent dunting from uneven tension, we recommend using Kiln Ice on the inside and outside of the ware.

Do extensive tests before pairing Kiln Ice with other glazes. Glazes that are particularly stiff (e.g. matte glazes) may make for poor partners. Kiln Ice glazes pair best with more fluid glazes.

For best results, always fire a test of any new combinations before glazing a large amount of ware.

Apply to: Cone 04 Bisqueware
Number of coats? 3-4 heavy coats
Fire to: Cone 5 - Cone 6
Food safe? Yes, but due to durability, these glazes are not recommended for food surfaces