Glaze Guidelines

Glazing is one of the most satisfying, yet volatile elements in ceramics. To ensure the success of our students and members, as well as the safety of the studio equipment, all students and members must follow these glaze guidelines.

Person painting a white ceramic mug with orange glaze in a workshop setting.

Proper Glaze Application

  • The lower 1/4 inch of each piece and the foot must be free of glaze before glaze firing.

  • Glaze should be applied in accordance with its unique properties (example: glazes and combinations prone to movement should not be applied as heavily on the bottom half of the piece).

  • Utilize standard glaze application techniques and tools for brushing and dipping. No spray application will be allowed in the studio.

  • Luster is not permitted.

  • We do not provide stilts for firing but you can provide your own if you would like us to stilt your piece while firing.

Close-up of blue and green ceramic vases with narrow necks.

Commercial Cone 4 - 6 Mid-Range Glazes Only

  • NPC will always glaze fire at cone 5 and bisque fire at cone 04.

  • NPC will only fire pieces with mid-range (cone 4-6) glazes applied.

  • Commercially made glazes only (must be AP or CL certified).

  • We will not fire commercial glazes that intentionally crawl, flake, shiver, foam, crater, pit, or blister including Ritual Brand glazes, and Mayco’s Magma glazes.

  • Glazes made by regional pottery retailers are allowed (Seattle Pottery Supply, Clay Art Center, Georgies).

  • Glazes should be recommended for use on cone 04 bisque.

  • If unsure if your glaze is appropriate for NPC firing, please email admin@nwpotterycollective.com or speak with staff during open studio hours.

  • We do not allow homemade glazes.

  • Open studio guests MUST use glazes provided by or purchased from NPC.

Northwest Pottery Collective reserves the right to not fire pieces that violate these guidelines in its kilns