Bullseye Copper Blue (style 001246) is a 90 COE fusible glass sheet, a transparent color for fusing, slumping, and kilnforming.
Cold characteristics Uniform color
Working notes May have dark color reaction at interface with cadmium/selenium or sulfur glasses. May have a red-hued color reaction with reactive glasses. Copper Blue may deposit a residue onto shelf releases (ThinFire, primer) when firing to a full fuse or hotter. Scrape and thoroughly buff off used primer, then apply fresh primer; or remove used Thinfire and replace with new to avoid possible contamination effects in subsequent firings. These contamination effects are essentially reactions, possible when Selenium, Sulfur and Reactive styles are fired while in contact with a copper-contaminated separator.
Reactions This is a reactive glass. It contains Copper (Cu) and may react where it meets Selenium (Se) / Sulfur (S), Reactive styles (000009, 001009, 001019), forming a visible line or halo at the boundary. Use that on purpose to outline and add depth, or keep reactive colors apart to avoid it.
Format and sizes Double-rolled sheet, 3mm standard thickness, with a rolled edge. Available in the sizes shown above.
Fusing and compatibility Tested compatible with other Bullseye glass. When you combine it with glass from other makers, matching COE alone does not guarantee compatibility, so fire a small test tile first.
More of This Color The same Bullseye color in other forms: 2mm Thin Sheet .
Helpful downloads What to Expect from Bullseye Glass (PDF) · Reactive Potential of Bullseye Glass (PDF)
Technical data courtesy of Bullseye Glass.
Description updated: July 7, 2026
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