Do NOT use a pencil sharpener. It is best to sharpen them with a knife or blade.
NOTE: The maximum firing temperature is Cone 10 for Blue, Black, and Green, Cone 5 for Brown and Yellow, and Cone 05 for Rose.
WARNING: This product can expose you to chemicals including Silica, crystalline (airborne particles of respirable size), which are known to the State of California to cause cancer. For more information go to www.P65Warnings.ca.gov.