Bullseye Glass Mold #8756, Drop Out Ring 13.3"

The Drop Out Ring mold #8756 from Bullseye Glass is a ceramic slumping form that supports the outer rim of a glass sheet while the center portion sags freely downward as the kiln heats. At 13.3 inches in outer diameter, the ring suits round plates, shallow bowls, and decorative panels made from sheet glass or fused blanks in that size range.

The ring stands 0.5 inches tall. It is slipcast from a specially formulated clay body by Creative Ceramics in Europe and imported by Bullseye Glass. The surface is exceptionally smooth, accepts kiln wash uniformly, and does not crack under repeated proper use. Because these forms are handmade, individual pieces vary slightly in size, so measure your mold before cutting glass to fit.

What does the Drop Out Ring mold make?
It slumps a round glass sheet so the center drops downward while the outer rim remains supported by the ring. The finished piece has a defined rim where the glass rested on the ring, with the center dropped to a depth set by your firing.

How does a drop out ring differ from a standard slump mold?
A standard slump mold is a concave form the glass sags into. A drop out ring supports only the outer edge of the glass and lets the center fall freely downward, so the depth of the drop is controlled by firing time and temperature rather than by the shape of a mold cavity.

What size glass blank do I need?
Your blank must be large enough to span the inner opening and rest on the ring rim. The outer diameter is 13.3 inches, but because these molds are handmade and vary slightly, measure your actual mold before cutting glass.

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

How do I prepare the mold before slumping?
Apply kiln wash or shelf primer evenly to the top surface of the ring where the glass will rest, and let it dry fully before placing your glass. Recoat as needed between firings.

Specifications

• SKU: 162947
• Manufacturer: Bullseye Glass (design #8756, item 008756-MOLD-M-EACH; slipcast by Creative Ceramics in Europe, imported by Bullseye)
• Store model code: BG8756
• Form type: Drop out ring slumping form
• Outer diameter: 13.3 inches (34 cm)
• Height: 0.5 inches (1 cm)
• Material: slipcast ceramic, exceptionally smooth surface, 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.

• Apply kiln wash or shelf primer evenly to the top surface of the ring where the glass will rest. Let it dry completely before placing your glass. A boron nitride primer such as ZYP Boron Nitride Mold Primer or a standard kiln wash both work well with this form.
• Measure your actual mold before cutting glass. The 13.3 inch dimension is the outer diameter used to check kiln fit; individual molds vary slightly because they are handmade.
• Center your glass blank over the ring so it rests evenly on the rim and the center spans the opening. The center will sag downward as the kiln heats; the depth of the drop is set by firing temperature and time.
• The mold is COE agnostic. Use a slumping schedule matched to your glass, and adjust the anneal soak temperature for your COE.
• Visually confirm the slump during firing if your kiln allows. Let the kiln cool fully before removing the piece. Recoat the ring surface 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, not a guarantee. Every kiln fires differently. Visually confirm the slump during firing and adjust as needed for your glass, kiln, and piece.

AFAP means as fast as possible, letting the kiln ramp at its own natural rate. Segment 2 drops the kiln quickly to the anneal soak temperature at 900 F, then holds for one hour. Segment 4 is the final cool to room temperature with the door closed at the kiln's natural rate. Note: Bullseye's published 1250 F / 1:30 schedule for this mold is for making a shallow plate with the mold placed directly on the kiln shelf, not elevated. For a deeper drop with the mold elevated, adjust the firing and confirm the drop visually.

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

Description updated: July 6, 2026

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