Mastering the Glass-Glo Firing Schedule for Brilliant Metallic Effects
If you love creating sparkling, metallic finishes on fused glass, Glass-Glo is a must-try surface application. This lead-free product is stabilized for glass, glazed ceramics, and enameled metals—giving artists shimmering color and sparkle that hold up beautifully through multiple firings. Below you’ll find everything you need to know about how to apply Glass-Glo and the exact firing schedule to achieve vibrant results.
What Is Glass-Glo?
Glass-Glo is a specialty surface colorant that creates a rich, metal-like or glittering effect on glass art. It can be mixed with water for a soft watercolor wash or with an oil-based medium for thicker, textured applications. Artists use brushes, sponges, or even Q-tips to paint directly on their glass.
Surface Prep for Best Adhesion
For full, even coverage and long-lasting color, the glass must have a slight texture or “tooth.” Three easy ways to create this surface:
- Sandblast the glass.
- Lightly scuff with extra-fine sandpaper or a diamond hand pad.
- Pre-fire a thin layer of clear powder at 1300–1310 °F with a 3–10 minute hold. This leaves a subtle, sandpaper-like texture.
Step-by-Step Glass-Glo Firing Schedule
Getting that signature metallic sparkle is all about a controlled ramp and hold. No matter what fusing process you’re using, always follow this slow, precise schedule:
FIRING SCHEDULE FOR GLASS-GLO (If you have projects that are thicker and larger, you will have to slow down your ramp times but your hold temps and times will be the same.):
250 DPH - 350F - Hold 10min.
350 DPH - 500F - Hold 10 min.
350 DPH - 1000F - Hold 20 min.
600 DPH - 1325 - 1500 (Depending on your process & results desired.)
Continue on with your annealing schedule.
Pro Tip: Always test your kiln with a sample bar first. Kiln calibrations vary, and a small test ensures true color development.
Key Firing Tips for Brilliant Color
- Leave peep holes open during firing to allow moisture to escape.
- Multiple layers welcome. Fire the first design on, then add a second layer and re-fire—the metallic finish will remain vibrant.
- Rinse thoroughly once cooled; any loose Glass-Glo not fused to the surface will wash away naturally.
Why Artists Love Glass-Glo
- Lead-free and safe for glass, ceramic, and enameled metal.
- Flexible application—use with water for watercolor effects or oil for thicker strokes.
- Maintains brilliance even after multiple firings.
Bring Dazzling Dimension to Your Glass Art
Whether you’re embellishing fused jewelry or adding drama to a large panel, Glass-Glo opens up endless design possibilities. Follow this proven firing schedule and surface-prep routine, and your finished piece will shine with professional metallic sparkle every time.
Leave a comment