Bullseye Glass Mold #8630, Round Slumper 7.5"

The Round Slumper 7.5 inch mold (Bullseye design #8630) is a slipcast ceramic slumping form sized to shape a pre-cut or pre-fused glass blank into a shallow round disc. A sheet of glass is placed over the form and the assembly is fired in the kiln, where heat softens the glass and gravity draws it down to conform to the shape. The outer mold dimensions are 7.5 inches across and 1 inch tall (19 x 3 cm).

The mold is made by Creative Ceramics in Europe from a specially formulated clay body, then imported and sold by Bullseye Glass. The surface is exceptionally smooth, accepts kiln wash uniformly, and does not crack under repeated proper use. Like all ceramic slumping forms, it is COE agnostic and reusable across many firings.

What does the Round Slumper 7.5 inch mold make?
It slumps a pre-cut or pre-fused glass blank into a shallow round disc about 7.5 inches in diameter.

What size glass do I need for this mold?
The outer mold dimensions are 7.5 inches by 1 inch tall. Because these molds are handmade, they vary slightly in size, so measure your specific mold before cutting glass rather than relying on the nominal dimension.

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

How do I prep the mold?
Coat the forming surface with a kiln wash such as Hotline Primo Primer and let it dry completely before placing glass on the mold. The smooth surface accepts kiln wash uniformly. Re-coat as needed between firings.

Specifications

• SKU: 5100
• Manufacturer: Bullseye Glass (design #8630, item 008630-MOLD-M-EACH; made by Creative Ceramics, imported by Bullseye)
• Store model code: BG8630
• Makes: 1 shallow round disc
• Finished piece size: about 7.5 inches diameter
• Outer mold dimensions: 7.5 inches diameter x 1 inch tall (19 x 3 cm)
• Material: slipcast ceramic kiln mold, 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 and let it dry completely before placing glass. You may also use a boron nitride mold primer such as ZYP Boron Nitride Mold Primer. The smooth surface accepts kiln wash uniformly.
• Place a pre-cut or pre-fused glass blank over the top of the form. These molds are handmade and vary slightly in size, so measure your mold before cutting glass rather than relying on the nominal measurement.
• The mold is COE agnostic. Use a slumping schedule matched to your glass, adjusting the anneal soak temperature for your COE.
• Visually confirm the slump during firing and adjust temperature as needed. Let the kiln cool fully before removing the finished piece.
• Re-coat the mold with kiln wash as needed between firings.

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. Visually confirm the slump during firing and adjust the schedule for your glass and kiln.

AFAP means as fast as possible (the kiln drops to that temperature at its maximum rate). Segment 4 is a natural cool to room temperature with the kiln door closed. Adjust the anneal soak temperature in segment 2 as needed for your glass COE.

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

Description updated: July 6, 2026

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