Small River Rocks Frit Casting Mold

The Small River Rocks Frit Casting Mold from Creative Paradise, designed by Mark Hufford, casts a collection of river rock shaped glass pieces in a single firing. The mold footprint is 6.25 inches by 6 inches, and the finished pieces range from 0.75 inch to 1.25 inches in length, reproducing the irregular, rounded shapes of smooth river stones. The naturally varied sizes within each batch make the pieces useful as texture accents in fused panels, mosaic fillers, jewelry components, and mixed-media decorative work.

Like all ceramic casting molds, this one is COE agnostic. Fill the cavities with frit, billets, or stacked sheet scrap and fuse so the glass takes the shape of each rock cavity. The total fill weight for the mold is 60 grams. As a kiln casting mold it is reusable across many firings when prepped and cared for properly.

What does the Small River Rocks mold make?
It casts a collection of river rock shaped glass pieces ranging from 0.75 inch to 1.25 inches in length in a single firing. The varied shapes work well as texture accents, mosaic fillers, jewelry components, or panel details.

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 for the mold?
Creative Paradise lists a total fill of 60 grams across all cavities. Weigh your glass before loading and test a first run when the result matters.

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: 167113
• Manufacturer: Creative Paradise (CPI.LF181)
• Designer: Mark Hufford
• Makes: river rock shaped glass pieces
• Finished piece size: 0.75 inch to 1.25 inches L
• Mold size: 6.25 inches L x 6 inches W x 1.5 inches T
• Total fill weight: 60 grams
• 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.
• Fill with frit, billets, or stacked sheet scrap, distributing glass across the cavities to a total of 60 grams. 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 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: Basic Frit Casting Tutorial (PDF) · Fill Weights for Casting Molds (PDF) · Casting Mold Tips (PDF)

Description updated: July 6, 2026

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