Mid-Fire 12-Color School Sampler Pack

Why are some items AP certified and others CL certified?

Both are certifications received from the Art and Creative Materials Institute as a result of extensive toxicological testing. AP is for products that contain no materials in sufficient quantities to be toxic or injurious to humans, including children, or to cause acute or chronic health problems. CL is for products that are labeled in accordance with the chronic hazard labeling standard and are certified to be not hazardous if used in accordance with directions on packaging.

What is the shelf life of Speedball glazes and underglazes?

Speedball glazes and underglazes have a shelf life of 2 years after manufacture, however when properly stored and maintained they can last much longer.

What firing process can I use to get the best results with Speedball Mid-Fire glazes?

To get the best results with Mid-Fire glazes, we recommend bisque firing to cone 05/04 and doing a test tile on your clay body and preferred firing method. We do not recommend any slow controlled cools, as this can effect the final appearance of the glaze.

Can Speedball Mid-Fire glazes be high fired to cone 10?

Yes, however the finished appearance of many of the glazes may change at higher temperatures. We recommend doing test tiles and your own dinnerware safety testing prior to use on any finished pieces.