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

color overview
Green Tourmaline is a gloss glaze that manifests a balance of yellows, blues, purples and greens creating a harmonious surface packed with depth. Benefiting from a thicker application, Green Tourmaline will continuously play a complex tune around any surface. When fired to Cone 5 this glaze brings out dynamic purple and blue tones. A good stir before application will help maximize color variations throughout the finish.
| Cone 5 Results | Glossy, blue and purple mottling |
| Cone 6 Results | Glossy, earthy green with blue and purple mottling |
| Recommended Layers | 3 heavy coats |
| Notes | No slow cool |