Wissmach Reactive Blue/ Black with Luminescent coating (base color code 96-38) is a Prisma blend in COE 96 kiln glass, deep blue and black streaks under an iridescent surface in a 3mm sheet, tested for fusing compatibility.
Appearance Deep teal blue clouds mottle across the sheet, shading into black where the second color pools, and the coating scatters patches of magenta, amber gold and green shimmer over the top. The rainbow effect shows in ordinary room light, no special lighting needed. Reactive Blue is first in the name and the more dominant, and the streaking is unique to each sheet, so no two are identical.
Striking Wissmach's Opaque and Prisma colors can strike to a deeper or denser color after firing, so the fired sheet may read a little richer than it looks now. A quick sample chip settles the question when shade matters.
Luminescent coating The Luminescent coating spreads a fiery shimmer over the deep blue and black streaks, flashing magenta, gold and green as the light and viewing angle change. The coating is a low fire surface layer and it is heat sensitive. Fired face up, heat and oxygen can burn it away. Wissmach recommends reverse fusing with the coated face down on a flat kiln shelf and keeping the top temperature at 1400 F or below. Do not cap the coated surface with clear glass, capping makes the coating disappear. Keep any later firings below 1250 F. For a full fuse with two 3mm layers, Wissmach’s Luminescent schedule runs 400 degrees F per hour to 1225 F with a 30 minute hold, then 600 per hour to 1400 F with a 10 minute hold, cooling as fast as the kiln allows to 960 F for a 1 hour hold, then 100 degrees F per hour down to 700 F. Results vary sheet to sheet, so test fire a small piece first.
Reactions The base blend carries copper on Wissmach's COE 96 chart. In direct contact with sulfur bearing colors such as String of Pearls, Oyster Pearl, Gold Tone or the red and orange family, it can form a darker reaction line where the glasses touch. Test the pairing first, whether you want the line or want to avoid it.
Format and sizes Sold as a 3mm sheet in 8" x 10.5", 10.5" x 16" and 16" x 21" sizes. Choose your size from the options on this page.
Fusing and compatibility Tested compatible with other Wissmach COE 96 kiln glass. With glass from other makers, a matching COE number alone does not guarantee compatibility, so fire a test tile before committing a project.
More of this color Also available without the coating (plain sheet) .
Helpful downloads Wissmach COE 96 Kiln Glass Catalog
Technical data courtesy of the Paul Wissmach Glass Co.
Description updated: August 13, 2026
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