Square Knobs Casting Mold

The Square Knobs Casting Mold from Creative Paradise casts four square glass knobs in a single firing, with each finished knob measuring 1.5 inches by 1.5 inches. The four cavities sit in a mold that is 5 inches by 5 inches by 2 inches tall, with a diagonal of 7 inches. Fiberfrax fiber paper is required for this project and must be on hand before you fire.

Like all ceramic casting molds, this one is COE agnostic. Fill the cavities with frit, small billets, or stacked sheet scrap and fuse to the square knob shape. The manufacturer lists 28 grams of glass per cavity. Hardware for mounting the finished knobs is sold separately. As a kiln casting mold, it is reusable across many firings when prepped and cared for properly.

What does the Square Knobs Casting Mold make?
It casts four square glass knobs, each 1.5 inches by 1.5 inches, in one firing. The finished pieces can be mounted as drawer or cabinet knobs using separately sold hardware.

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 much glass do I need per knob?
Creative Paradise lists 28 grams per cavity. Fill weight varies with how full you pack each cavity, so weigh your glass and test a first run when the result matters.

How do I prep this mold before casting?
Coat the cavities with a kiln shelf primer such as a boron nitride spray or kiln wash, and let it dry completely before adding glass. Fiberfrax fiber kiln paper is also required for this project and should be used as directed during firing.

Specifications

• SKU: 12986
• Manufacturer: Creative Paradise (CPI.LF52)
• Makes: 4 square knobs
• Finished piece size: 1.5 inches L x 1.5 inches W each
• Mold size: 5 inches L x 5 inches W x 2 inches T
• Diagonal: 7 inches
• Suggested fill weight: 28 grams per cavity
• Required accessory: Fiberfrax fiber kiln paper
• Hardware: sold separately
• 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 such as Hotline Primo Primer, and let it dry completely before adding glass so the glass does not stick.
• Fiberfrax fiber kiln paper is required for this project. Place it as directed to support the mold properly during firing.
• Fill with frit, small billets, or stacked sheet scrap. For a tack fired surface, the manufacturer suggests powder and fine frit filled uniformly to about a quarter inch.
• The mold is COE agnostic. Use a full fuse schedule matched to your glass, adjusting the final anneal soak for your COE.
• Let the kiln cool fully before removing the cast knobs. Re coat the mold with primer as needed between firings. Hardware for mounting the finished knobs is sold separately.
• 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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