Branches Casting Mold

The Branches Casting Mold from Colour de Verre fills three separate twig cavities in a single firing, producing cast glass twig elements designed to complement blossoms, leaves, and other botanical fused glass compositions. A built-in slumper on the reverse side of the mold lets you shape the castings in a separate slump firing after the casting firing, giving each twig a dimensional, lifelike undulating shape.

The mold measures 5 inches by 8.75 inches by 1.25 inches and holds three distinct twig designs. Colour de Verre lists fill weights of 7, 23, and 32 grams for the three cavities. Like all ceramic casting molds, it is COE agnostic and reusable across many firings when prepped and cared for properly.

What does the Branches Casting Mold make?
It casts three twig shaped glass pieces, one per cavity, in a single firing. The three cavities are each a distinct design, with fill weights of 7, 23, and 32 grams. The built-in slumper on the reverse of the mold adds gentle undulation to the finished castings.

What is the built-in slumper on the reverse side?
The back of the mold has a contoured slumping surface. After the casting firing, place the fired twigs over it and run a separate slump firing so each twig takes on a natural, dimensional shape rather than lying completely flat.

How much glass do I need per cavity?
Colour de Verre lists fill weights of 7, 23, and 32 grams for the three twig designs. Weigh your frit carefully and test a first run when the result matters.

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 and anneal soak to the glass you are using.

Specifications

• SKU: 181086
• Manufacturer: Colour de Verre
• Makes: 3 twig shaped glass pieces (3 distinct designs per firing)
• Mold size: 5 inches x 8.75 inches x 1.25 inches
• Suggested fill weights: 7, 23, and 32 grams per cavity
• Features: built-in slumper on reverse side for a separate slump firing after casting
• 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 all cavities before every firing with ZYP Boron Nitride Mold Primer or Hotline Primo Primer and let the coating dry completely before adding glass so the castings release cleanly. Re-coat before each firing.
• Fill each cavity with frit to the suggested weights: 7 grams, 23 grams, and 32 grams for the three twig designs. Weigh your frit for consistent results.
• The built-in slumper on the reverse side shapes the castings in a separate slump firing after the casting firing.
• The mold is COE agnostic. Use a firing schedule matched to your specific glass and adjust the anneal soak accordingly.
• Let the kiln cool fully before removing the castings.

Suggested Firing Schedule

This is a suggested starting point, 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 during the initial ramp to avoid thermal shock.
• Colour de Verre recommends a target casting temperature of about 1350 F for COE96 glass and about 1375 F for COE90 glass.
• Fire to no more than about 1450 F (785 C).
• After the casting soak, cool with a controlled ramp and add an anneal soak appropriate for your glass COE.
• Let the kiln cool fully before removing the castings and re-coat the mold before the next use.

Helpful downloads: Pine Cone Candle Chimney (PDF) · Autumn Leaf Platter (PDF) · Priming with ZYP Spray (PDF) · Tricks of the Trade (PDF) · Peach Blossom Box (PDF) · Branches, Pine Cones and Small Leaves (PDF)

Description updated: July 6, 2026

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