Bullseye Glass Mold #8788, Swirl Bowl 11.9"

The Swirl Bowl mold from Bullseye Glass (design number 8788) is an 11.9 inch ceramic slumping form that shapes a glass sheet or fused blank into a swirled bowl as it softens in the kiln. The outer mold dimensions are 11.9 inches by 2.1 inches (30 by 5 cm), which you can use to confirm the mold fits your kiln shelf. These molds are handmade by Creative Ceramics in Europe and vary slightly in size from piece to piece, so measure your specific mold before cutting glass rather than relying on the listed dimensions alone.

Slipcast from a specially formulated clay body, this form features an exceptionally smooth surface that accepts kiln wash uniformly and holds up through repeated firings with proper care. The technique is straightforward: coat the forming surface, set your glass on the mold, and fire a slumping schedule suited to your glass. Like all ceramic slumping forms, it is COE agnostic and works with COE90, COE96, or other compatible fusible glass.

What does the Swirl Bowl mold make?
It slumps a flat glass blank into a bowl with a swirl form, roughly 11.9 inches across. Start with a pre-cut sheet or a fused blank sized to fit the mold surface.

What COE glass can I use with this mold?
Any COE. Ceramic slumping forms are COE agnostic, so the same mold works with COE90, COE96, or other compatible fusible glass. Match your firing schedule and anneal soak temperature to the glass you are using.

How do I size my glass blank for this mold?
The listed outer dimensions are 11.9 inches by 2.1 inches. Because these molds are handmade and vary slightly in size, measure your specific mold before cutting glass; do not rely on the listed dimensions alone.

How do I prep the mold before firing?
Coat the forming surface with a kiln wash such as Hotline Primo Primer or a shelf primer and let it dry fully before placing glass. Re-coat between firings as needed to ensure clean release.

Specifications

• SKU: 159243
• Manufacturer: Bullseye Glass (design #8788, item 008788-MOLD-M-EACH; slipcast by Creative Ceramics in Europe, imported by Bullseye)
• Store model code: BG8788
• Makes: one slumped swirl bowl
• Mold outer size: 11.9 inches L x 2.1 inches H (30 x 5 cm)
• Material: slipcast ceramic kiln slumping form, reusable
• Glass: 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 shelf primer such as ZYP Boron Nitride Mold Primer, and let it dry completely before placing glass so the piece releases cleanly after firing.
• Place a pre-cut glass sheet or fused blank on the mold. These molds are handmade and vary slightly in size, so measure your mold before cutting glass rather than relying on the listed dimensions.
• The mold is COE agnostic. Fire a slumping schedule matched to your glass, adjusting the anneal soak temperature for your COE (about 900 F for COE90 or 950 F for COE96).
• Visually confirm the slump is complete during firing. Let the kiln cool fully before removing the piece.
• Re-coat the forming surface with kiln wash between firings as needed.

Bullseye Suggested Slumping Schedule

This is a suggested starting schedule based on slumping 6mm pieces in a Paragon GL24 kiln, not a guarantee. Every kiln fires differently and glass viscosity varies by style. Visually confirm the slump during firing and adjust the schedule for your glass and kiln.

Segment 2 targets 900 F, the standard anneal soak for COE90. If using COE96, adjust this soak to 950 F. AFAP means as fast as possible at the kiln's natural rate. Segment 4 means let the kiln cool with the door closed to room temperature.

Helpful downloads: Suggested Slumping Schedules from Bullseye Glass (PDF)

Description updated: July 6, 2026

Spot an error or have feedback on this description? Report it here.