Wissmach Crystal/ Superior Blue with Luminescent coating (base color code 96-24) is a Prisma blend in COE 96 kiln glass, pale blue streaks under an iridescent surface in a 3mm sheet, tested for fusing compatibility. Wissmach's name for the base blend is Cornflower Blue/Crystal.
Appearance The base reads as a soft periwinkle blue with paler zones where the clear crystal streaks through, and the coating washes the whole surface in mint, lavender and aqua shimmer that moves with your viewing angle. The rainbow effect shows in ordinary room light, no special lighting needed. Cornflower blue leads the base blend, and the streaking is unique to each sheet, so no two are identical.
Striking The base blend is a Prisma, so it may strike a shade deeper or denser in the firing, as Wissmach notes for its Opaque and Prisma colors. Fire a sample chip first if the exact tone matters.
Luminescent coating The Luminescent coating lays a mother of pearl shimmer over the cornflower blue and crystal streaks, drifting through mint green, lavender and aqua 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 is not flagged on Wissmach's COE 96 reactive chart. It sits next to any color in the line without forming a reaction line, so you can pair it freely without planning around chemistry.
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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