How to Glaze
Glaze Approval System
Glazes not already on our approved list must go through a testing process before use on any studio kilns.
Steps for Glaze Testing:
- Create a Test Piece: Make a small item no larger than 6" x 6" x 6" (e.g., mug, bowl, sculpture). If you do not have a piece, a vertical test tile made from Cinco Blanco will be provided by Asmbly.
- Apply Your Glaze: Glaze your piece or tile using the same technique, layering, color overlaps, and number of coats you intend to use on your final work. Leave at least 1" of unglazed ceramic at the bottom of a piece, or 1/4" to 1/2" if using a test tile.
- Label Clearly: Write your name and glaze name on the tile or piece.
- Submit to Glaze Test Shelf: Place on the designated Glaze Test shelf near the kilns.
- Wait for Firing: A glaze fire will be scheduled based on kiln availability.
- Assessment Criteria: Glazes will be assessed for running, pinholing, crazing, blistering, and any risk to kilns or others’ work.
- Approval or Feedback: If your glaze passes, it will be added to the approved list. Otherwise, you will receive feedback for adjustments.
Note: Be prepared to possibly lose your test piece in the process.
Glaze Testing & Approval Policy
To protect the integrity of our kilns, the safety of our members, and the quality of everyone’s work, we enforce a strict glaze approval policy. Only clearly defined and approved materials are permitted for use in the studio.
What Is Allowed
We only accept commercially manufactured glazes, in the following forms:
- Pre-Mixed Commercial Glazes Liquid glazes sold ready-to-use by established ceramic glaze manufacturers (e.g., Amaco, Mayco, Laguna etc.).
- Studio-Approved Commercial Dry Glazes Powdered commercial dip glazes that are reconstituted under conditional supervision within the studio. These glazes must:
- Come directly from a commercial distributor
- Be mixed by or in coordination with designated studio personnel
- Receive prior approval from Seth or Perla
Members are not allowed to bring in, store, or mix dry commercial glaze powders on their own, even if the materials are from reputable sources. All glaze mixing must be supervised and approved in advance.
What Is Not Allowed
The following are strictly prohibited in the studio:
- Any homemade, member-formulated, or DIY glaze recipes, regardless of their source (e.g., books, online, ceramic blogs)
- Any mixture of raw glaze materials (oxides, frits, fluxes, etc.) sourced independently by members
- Any glaze materials or combinations that do not appear as a finished product in a commercial glaze bottle
- Mixing glaze powders outside the studio, including in outdoor common areas like the parking lot
To be clear: If it isn’t sold as a finished glaze product or mixed under the supervision of approved studio personnel, it is not allowed.
Mixing Policy
- No unsupervised mixing of glaze materials is allowed, including reconstituting commercial dry dip glazes.
- Approved commercial dry glazes may be mixed only:
- Under the supervision of Seth, Perla, or another designated person
- In controlled and designated areas with proper PPE and ventilation
- Members are not permitted to bring in raw glaze materials or mix their own glazes in any studio or public area.
Glaze Testing
- All test firings must be approved and scheduled independently from regular kiln loads.
- A separate test kiln will be used when appropriate.
- The topmost studio shelves are designated for placing test pieces (bisque or glaze tests) and will be clearly labeled.
Approval & Communication
All materials not currently on the approved list must be reviewed and explicitly approved before use.
For approvals, contact:
- Seth White – seth.white@asmbly.org
- Perla Darnell – perla.darnell@asmbly.org
Email is the preferred and most reliable method of communication.
Summary
- Only studio-approved commercial glazes are permitted — no exceptions.
- Dry commercial glazes may only be mixed under supervision — members cannot mix on their own or off-site.
- No homemade recipes, experimental blends, or member-sourced raw materials are allowed.
- All glaze testing is separate from regular firings and must be placed on designated shelves.
- Email Seth or Perla for all material approval and testing coordination.
By following these rules, we ensure a safe and respectful shared studio for everyone.
