PLC6CR Firing Schedule

Cone 6 Crystal Glaze Plainsman

Five-Step firing with no holds

Start temperature assumed: 25°C
Step Rate to Temp °C Rate
To °F Hold Accum
1 176°C/hr to 372 316 701   2:08  
2 398°C/hr to 1093 716 1999   3:57  
3 65°C/hr to 1210 117 2210   5:45  
4 398°C/hr to 1093 716 1999   6:03  
5 398°C/hr to 1037 716 1898   6:11  
*Rates are expressed as "Celcius/Fahrenheit degrees", temperatures as "Degrees celcius/fahrenheit"

With the advent of computer controlled kilns, producing crystal glazes at medium and high temperatures is quite easy, just use a really fluid zinc glaze and fire a schedule that gives them opportunity to grow.

Adjust the final temperature on step 3 to match the temperature your kiln reads when it reaches cone 6.

Note that almost everyone who uses crystalline glazes either does not notice or has accepted the crazing that these naturally produce on typical porcelain clay bodies at middle at high temperatures. This is not necessary, a high expansion clay body can be employed to prevent this.

In Bound Links

  • (Recipes) G2902B - Cone 6 Crystal Glaze

    2012-12-05 - This is from an article at

  • (Glossary) Crystalline glazes

    Crystals can form during cooling and solidification in many kinds of glazes and they can be microscopic or very large, widely scattered or completely covering. Matte glazes (e.g. high CaO) are often such because of a dense mesh of micro-crystals growing on the surface. Unwanted crystallization is ca...

By Tony Hansen

•The secret to cool bodies and glazes is a lot of testing.
•The secret to know what to test is material and chemistry knowledge.
•The secret to learning from testing is documentation.
•The place to test, do the chemistry and document is an account at
•The place to get the knowledge is

Sign-up at today.

Feedback, Suggestions

Your email address


Your Name


Copyright 2003, 2008, 2015, All Rights Reserved