The Classic Bowl mold from Bullseye Glass (design #8748) is a ceramic slumping form that shapes a pre-cut or fused glass blank into a shallow round bowl about 5.9 inches in diameter. Place the glass blank on top of the form, load it into your kiln, and fire to the slump temperature. The glass softens and settles by gravity to conform to the bowl profile, then you anneal and cool it slowly.
The outer dimensions of the mold are 5.9 inches by 1 inch (15 by 3 cm). These measurements are for kiln shelf planning and lid clearance. Because each mold is handmade, individual pieces vary slightly in size, so measure your mold before cutting glass to fit. The mold is slipcast from a specially formulated clay body by Creative Ceramics in Europe and imported and sold by Bullseye Glass. The surface accepts kiln wash uniformly and holds up well across many firings when properly cared for.
What does this mold make?
How does slumping with this mold work? Hotline Primo Primer and let it dry, then place a glass blank on top of the mold. As the kiln heats, the glass softens and drapes over the form by gravity, taking on the bowl profile. After the slump hold, anneal and cool the piece slowly.
What size glass blank do I need?
What COE glass works with this mold?
How do I prep and care for the mold?
Specifications
SKU: 152852Manufacturer: Bullseye Glass (made by Creative Ceramics, Europe; design #8748, item 008748-MOLD-M-EACH, store code BG8748)Makes: 1 classic round bowlMold outer size: 5.9 x 1 in (15 x 3 cm), for kiln fit planning; handmade, measure before cutting glassMaterial: slipcast ceramic slumping form, reusableGlass: any COE (COE agnostic)
Working Notes
These are guidelines, not guarantees. Every kiln fires a little differently, so test a small piece first when the result matters and follow a slumping schedule suited to your glass and kiln.
Coat the forming surface with kiln wash or a boron nitride mold primer such as ZYP Boron Nitride Mold Primer , and let it dry completely before placing glass so the glass releases cleanly after firing.
Measure your mold before cutting glass. Each piece is handmade and dimensions vary slightly from the listed size.
Place the glass blank on top of the mold and fire. The glass softens and conforms to the bowl profile by gravity. Confirm the slump visually during firing and remove the kiln from the slump hold once the glass has fully settled.
The mold is COE agnostic. Adjust the anneal soak temperature for your glass: about 900 F for COE90 or 950 F for COE96.
Let the kiln cool fully before opening and removing the piece. Recoat the mold surface with kiln wash as needed between firings.
Bullseye Suggested Slumping Schedule
This is a suggested starting schedule based on Bullseye's guidance for slumping 6mm glass in a Paragon GL24, not a guarantee. Every kiln fires differently and glass viscosity varies by style. Confirm the slump visually during firing and adjust the schedule for your glass and kiln.
Segment Description Rate Temp (F) Hold 1 Slump 300 F/hr 1225 1:30 2 Anneal soak AFAP 900 1:00 3 Anneal cool 100 F/hr 700 none 4 Cool AFAP 70 none
AFAP means as fast as possible at the kiln's natural rate. Segment 2 anneal soak is at 900 F, suited to COE90 glass. For COE96 glass, raise the anneal soak to 950 F. Segment 4 is a natural cool to room temperature with the kiln door closed.
Helpful downloads: Suggested Slumping Schedules from Bullseye Glass (PDF)
Description updated: July 6, 2026
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