Wissmach Crystal/ Irish Green Transparent/ White with Luminescent coating (base color code 96-WO 191) is a Prisma blend in COE 96 kiln glass, streaky green and white in a 3mm sheet with an iridescent surface, tested for fusing compatibility. Wissmach's own name for the blend is Apple.
Appearance Mossy and yellow greens streak horizontally through the sheet, softened by hazy patches of white and crystal, while the coating floats pearly lavender and pink flashes over the whole field. The rainbow effect shows in ordinary room light and shifts as the sheet tilts. Prisma streaking is unique to each sheet, so no two are identical, and the green carries most of this one with the white and crystal weaving through.
Striking The base is one of Wissmach's Prisma blends, which the maker notes may strike to a deeper or denser color after firing. Count on the fired greens coming out a little richer than the unfired sheet, and fire a test chip if the exact balance matters.
Luminescent coating The Luminescent coating floats a mother of pearl shimmer over the apple green blend, flashing lavender, pink 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 blend is a copper bearing color on Wissmach's COE 96 chart. Fired 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 line where the glasses touch. Test the pairing first when the outcome matters.
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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