The Square Drop Out 9.5 inch mold from Bullseye Glass (design number 8957) is a ceramic slumping form that supports a glass sheet along its outer rim while the center area softens and drops through a 5.4 inch square interior opening. The result is a glass piece with a square recessed center, suited to functional dishes, shallow trays, or decorative wall work.
The mold is slipcast from a specially formulated clay body by Creative Ceramics in Europe and imported by Bullseye Glass. The outer footprint is 9.5 by 9.5 inches with a profile height of 0.7 inches, making it a compact form that fits in most standard kilns without difficulty. The surface is exceptionally smooth, accepts kiln wash uniformly, and does not crack under repeated proper use.
What does the Square Drop Out 9.5 inch mold make?
What size glass sheet do I cut for this mold?
What COE glass can I use with this mold?
How do I prep the mold before slumping?
Specifications
SKU: 156615Manufacturer: Bullseye Glass (made by Creative Ceramics; design number 8957, item number 008957-MOLD-M-EACH)Makes: square drop out slumped glass pieceOuter mold size: 9.5 x 9.5 x 0.7 in (24 x 24 x 2 cm)Interior opening: 5.4 x 5.4 in (14 x 14 cm)Material: slipcast ceramic kiln slumping form, reusableGlass: any COE (COE agnostic)
Working Notes
These are guidelines, not guarantees. Every kiln fires a little differently, so test a piece first when the result matters and follow a slumping schedule suited to your glass and kiln.
Coat the forming surface with a kiln wash or shelf primer, such as ZYP Boron Nitride Mold Primer , and let it dry completely before placing glass on the mold. Re-coat as needed between firings.
These molds are made by hand and vary slightly in size. Measure your specific mold before cutting glass rather than relying only on the listed outer dimensions.
Cut your glass sheet to span the mold with the edges resting on the outer rim, centered over the 5.4 inch square interior opening so the center can drop freely during the slump.
The mold is COE agnostic. Use a slumping schedule matched to your glass COE, adjusting the anneal soak temperature accordingly.
Let the kiln cool fully before removing the slumped piece. Re-coat the mold with kiln wash or primer as needed between firings.
Bullseye Suggested Slumping Schedule (Fahrenheit)
This is a suggested starting schedule for slumping 6mm glass in a Paragon GL24 kiln, not a guarantee. Every kiln fires differently and glass styles vary in viscosity. Visually confirm the slump during firing and adjust the schedule for your glass, mold depth, and kiln.
Segment Rate (F/hr) Temp (F) Hold 1 (slump) 300 1250 1 hr 30 min 2 (anneal soak) AFAP 900 1 hr 3 (anneal cool) 100 700 none 4 (cool) AFAP 70 none
AFAP = as fast as possible. Segment 4 means letting the kiln cool at its natural rate with the door closed until room temperature is reached. The anneal soak at 900 F in segment 2 is suited to COE90 glass (standard Bullseye glass). If slumping COE96 glass, adjust the anneal soak to approximately 950 F. 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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