Round Knobs Casting Mold

The Round Knobs mold from Creative Paradise casts four round glass knobs, each 1.25 inches in diameter, in a single firing. The four cavities sit in a square mold footprint of 4.25 inches by 4.25 inches, with a diagonal of 6 inches, making it a compact mold for a practical batch of finished hardware pieces.

Glass knobs are a popular home accent and a common request from friends, family, and customers. Fill each cavity with frit, billets, or stacked sheet scrap and fuse to shape. Fiberfrax kiln shelf paper is required for this project. Like all ceramic casting molds, this one is COE agnostic and reusable across many firings when prepped and cared for properly.

What does the Round Knobs mold make?
It casts four round glass knobs, each 1.25 inches in diameter, in one firing. Finished knobs work as drawer pulls or cabinet hardware when fitted with the appropriate mounting hardware.

What is Fiberfrax and why is it required?
Fiberfrax is a ceramic fiber kiln shelf paper that supports the mold and protects the kiln shelf during firing. Creative Paradise lists it as required for this project.

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

How do I prep the mold before casting?
Coat the cavities with a kiln shelf primer such as a boron nitride spray (for example ZYP) or a kiln wash such as Hotline Primo Primer, and let it dry completely before adding glass. Re coat as needed between firings.

Specifications

• SKU: 12985
• Manufacturer: Creative Paradise (LF51)
• Makes: 4 round knobs
• Finished piece size: 1.25 inches diameter each
• Mold size: 4.25 inches L x 4.25 inches W
• Diagonal: 6 inches
• Suggested fill weight: about 16 grams per cavity
• Requires: Fiberfrax kiln shelf paper
• Material: ceramic kiln casting mold, reusable
• Glass: any COE (COE agnostic)

Working Notes

These are guidelines, not guarantees. Every kiln fires a little differently, so test a small run first when the result matters and follow a casting schedule suited to your glass and kiln.

• Prime the cavities with a boron nitride mold primer such as ZYP Boron Nitride Mold Primer, or a kiln wash, and let it dry completely before adding glass so the glass does not stick.
• Fiberfrax kiln shelf paper is required for this project. Fiberfrax 1/8 inch Fiber Kiln Shelf Paper is available separately.
• Fill with frit, small billets, or stacked sheet scrap. For a tack fired surface, fill uniformly to about a quarter inch with powder and fine frit.
• The mold is COE agnostic. Use a full fuse schedule matched to your glass, adjusting the final anneal soak for your COE.
• Mounting hardware for finished glass knobs is available separately. See Drawer Knobs Casting Mold Hardware.
• Let the kiln cool fully before removing the cast pieces. Re coat the mold with primer as needed between firings.
• The Slide Hi Temp brand separator is not recommended with these molds.

Creative Paradise Suggested Firing Schedule

This is a suggested COE96 starting schedule, not a guarantee. Every kiln fires differently. Test a small run and adjust the schedule for your glass and kiln.

Full Fuse (COE96):

Tack Fire (COE96): for a tack fired surface, fill uniformly to about a quarter inch with powder and fine frit.

*Segment 4 is the anneal soak at 950 F for COE96. If using COE90, adjust this temperature to 900 F.

Helpful downloads: Knobs and Pulls Tutorial (PDF) · Fill Weights for Casting Molds (PDF) · Casting Mold Tips (PDF)

Description updated: July 6, 2026

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