Wissmach Black/ Oyster Pearl with Luminescent coating (base color code 96-36) is a Prisma blend in COE 96 kiln glass, black and warm pearl streaks under an iridescent surface in a 3mm sheet, tested for fusing compatibility.
Appearance Horizontal streaks of smoky black and soft ivory pearl flow across the sheet, and the coating floats bands of lavender, mint green and pale gold over them, so the whole surface reads like abalone shell. The rainbow effect shows in ordinary room light. Prisma is Wissmach's blend of two or three colors in one sheet, and the first color in the name is the more dominant, so black leads with the pearl weaving through it. The streaking is unique to each sheet, so no two are identical.
Striking As with Wissmach's other Opaque and Prisma colors, the base glass may strike to a deeper or denser color after firing, so expect the fired result a little richer than the unfired sheet. Fire a sample chip if the exact balance of black and pearl matters.
Luminescent coating The Luminescent coating lays a mother of pearl shimmer over the black and oyster pearl streaks, washing the sheet in lavender, seafoam green and silvery grey 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 sulfur on Wissmach's COE 96 chart. Fired in direct contact with a copper bearing color such as Reactive Blue, Deep Sky Blue, Turquoise Green or Sea Blue, it can form a darker reaction line where the glasses meet. Test the pairing first if 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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