Bullseye Glass Mold #8643, Double Curve Slumping Mold 15.9"

The Double Curve Slumping Mold from Bullseye Glass is a large slipcast ceramic form measuring 15.9 by 13.6 inches, with a depth of 2.9 inches. A glass sheet or fused blank is placed over or into the form, then fired so gravity eases the softened glass into the form's contours. The finished piece carries a flowing compound curve suited to display platters, decorative panels, and sculptural glass work.

The mold is slipcast from a specially formulated clay body by Creative Ceramics in Europe and imported by Bullseye Glass. Its surface is exceptionally smooth, accepts kiln wash uniformly, and holds up across many firings when prepped and cared for properly. Like all ceramic slumping forms, it is COE agnostic: use it with COE90, COE96, or other fusible glass, and match your firing schedule to the glass you are using.

What does the Double Curve mold make?
It slumps a glass sheet or fused blank into a double curve form. The finished piece is suited to display platters, decorative architectural panels, and sculptural glass work.

What size glass do I need?
The listed dimensions, 15.9 by 13.6 inches, are the outer mold dimensions used to check kiln fit. These molds are handmade and vary slightly in size, so measure your specific mold before cutting glass to determine the right blank size for the forming area.

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

How do I prep this mold before slumping?
Coat the forming surface with kiln wash or a boron nitride primer and let it dry completely before placing your glass. A smooth, even coat prevents the slumped piece from sticking to the mold surface.

Specifications

• SKU: 164850
• Manufacturer: Bullseye Glass (made by Creative Ceramics in Europe, imported by Bullseye; design number 8643, item number 008643-MOLD-M-EACH)
• Store model code: BG8643
• Mold type: Double curve slumping form
• Outer dimensions: 15.9 in L x 13.6 in W x 2.9 in D (40 x 35 x 7 cm)
• Material: slipcast ceramic, reusable
• Surface: exceptionally smooth, accepts kiln wash uniformly
• Glass: any COE (COE agnostic)

Working Notes

These are guidelines, not guarantees. Every kiln fires 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. Let the coating dry completely before placing your glass blank.
• Lay your glass sheet or fused blank over or into the mold. The listed dimensions are the outer mold measurements: measure your specific mold before cutting glass, as these molds are handmade and vary slightly in size.
• The mold is COE agnostic. Use a slumping schedule matched to your glass. Adjust the anneal soak for your COE: about 900 F for COE90 or 950 F for COE96.
• Visually confirm the slump during firing. Once the glass has fully settled into the form, proceed to the anneal soak.
• Let the kiln cool fully before removing the slumped 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 glass in a Paragon GL24 kiln, not a guarantee. Every kiln fires differently. Follow Bullseye's published Suggested Slumping Schedule for your glass and mold depth, and test a small piece first.

AFAP means as fast as possible: let the kiln drop to the target temperature at its natural rate, door closed, for those segments.

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

Description updated: July 6, 2026

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