Wissmach White/ Dark Blue with Luminescent coating (base color code 96-28) is a Prisma blend in COE 96 kiln glass, blue and white streaks under an iridescent surface in a 3mm sheet, tested for fusing compatibility. Wissmach's name for the base blend is White/Midnight Blue.
Appearance Under the coating, the white and midnight blue streaking reads as soft violet blue ribbons running the length of the sheet, washed with green and gold shimmer that shifts as you move around it. The rainbow effect shows in ordinary room light, no special lighting needed. White is first in the base blend's name and the more dominant, and the streaking is unique to each sheet, so no two are identical.
Striking The base blend is a Prisma, and Wissmach notes its Opaque and Prisma colors may strike to a deeper or denser color after firing. Expect the fired result a little richer than the unfired sheet, and test a chip when the shade is critical.
Luminescent coating The Luminescent coating lays a pearly rainbow over the white and midnight blue streaks, drifting through violet, green and gold 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 glass carries copper on Wissmach's COE 96 chart. In direct contact with sulfur bearing colors such as String of Pearls, Oyster Pearl, Honey or the red and orange family, it can form a darker reaction line where the glasses touch. Prove the pairing on a small test tile first when the effect matters to your design.
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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