Elliptical Box

The Elliptical Box mold set from Colour de Verre is a two-mold ceramic casting set that produces a glass box with a fitted lid. The base mold measures approximately 8 inches by 5 inches by 2.5 inches deep, and the two molds work together so the finished lid fits the finished base. This is a frit-casting set: glass material is loaded directly into each cavity, fired so it takes the cavity shape, and the result is a formed glass box.

Each mold accepts a wide range of glass materials: frit of any mesh, billets, casting rocks, nuggets, pebbles, cut or broken sheet glass, or nipped rods. The base cavity calls for about 375 grams and the lid cavity for about 180 grams. Both molds are ceramic and COE agnostic, reusable across many firings when properly primed and cared for. Colour de Verre recommends this set for intermediate to advanced fused glass artists.

What does the Elliptical Box mold set make?
It casts a two-piece glass box: an elliptical base and a matching lid. Each piece is fired separately in its own mold, then the two are combined once cooled.

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

How much glass do I need for each piece?
Colour de Verre lists about 375 grams for the base cavity and about 180 grams for the lid cavity. Weigh your glass and test a first firing when the result matters.

Can I decorate the finished pieces?
Yes. Once cast and annealed, you can tack fuse decorative elements onto the base or lid in a second firing. Colour de Verre notes their blossom, butterfly, scarab, pine cone, dragonfly, and leaf castings as examples suited to these forms.

Who is this set designed for?
Colour de Verre recommends this set for intermediate to advanced fused glass artists who want to explore more complex hollow forms and multi-firing techniques.

Specifications

• SKU: 181668
• Manufacturer: Colour de Verre
• Makes: 1 glass elliptical box (base and matching lid, two separate molds)
• Base mold size: approx. 8 inches L x 5 inches W x 2.5 inches deep
• Base fill weight: about 375 grams
• Lid fill weight: about 180 grams
• Material: ceramic kiln casting molds, reusable
• Glass: any COE (COE agnostic)
• Skill level: intermediate to advanced

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 the Colour de Verre project sheet for this mold.

• Prime both mold cavities before every use. Colour de Verre specifically recommends ZYP Boron Nitride Mold Primer or Hotline Primo Primer. Let the primer dry completely before adding glass.
• Fill the cavities with frit (any mesh), billets, casting rocks, nuggets, pebbles, cut or broken sheet glass, or nipped rods. The base takes about 375 grams and the lid about 180 grams.
• Both molds are COE agnostic. Use a firing schedule matched to the glass you are using, and adjust the anneal soak temperature for your COE.
• Fire each mold in a separate firing if needed, or confirm they both fit in your kiln at the same time.
• Let the kiln cool fully before removing the cast pieces. Re-prime the molds before each subsequent firing.
• Once cast and annealed, you can tack fuse decorative elements onto the base or lid in a second firing.

Suggested Firing Schedule

This is a suggested starting schedule, not a guarantee. Every kiln fires differently. Follow the Colour de Verre project sheet for this mold and test a small run before committing to a full batch.

• Heat no faster than about 350 F (195 C) per hour through the heat-up stages to avoid thermal shock to the mold and glass.
• Fire to no more than about 1450 F (785 C) at the top of the casting cycle.
• Add a controlled cool with an anneal soak suited to your glass: about 950 F for COE96, or about 900 F for COE90.
• Do not rush the cool-down. Let the kiln reach room temperature before opening.

Helpful downloads: Priming Molds With ZYP Spray (PDF)

Description updated: July 6, 2026

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