How to Glaze
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.
How to Test a Glaze
- Use a test piece (under 6" x 6" x 6") or request a vertical test tile from Asmbly (Cinco Blanco clay)
- Apply your glaze fully using the same number of coats, layering, and techniques you intend for your final work
- Leave 1" unglazed at the bottom of ceramic test pieces
- Leave 1/4"–1/2" unglazed on provided vertical test tiles
- Label the piece or tile with your name and the glaze name
- Place on the Glaze Test Shelf near the kilns
- Wait for glaze fire (scheduled based on kiln availability)
- Results will be assessed for running, crazing, blistering, or risk to kiln/kiln furniture
Please Note:
- You may lose the test piece
- Approved glazes will be added to our studio list.
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.
