Wissmach Crystal/ Dark Red Transparent with Luminescent coating (base color code 96-64) is a Prisma blend in COE 96 kiln glass, crystal and dark red streaks under an iridescent surface in a 3mm sheet, tested for fusing compatibility.
Appearance The blend reads warm apricot and peach across the sheet, with rose pink drifts where the red streaks thicken and paler zones where the crystal leads, all under a soft pearl shimmer that shows in ordinary room light. A scatter of fine seeds rides in the glass. Crystal is the first color in the name and the more dominant, and the streaking is unique to each sheet, so no two are identical.
Striking Wissmach notes its Opaque and Prisma colors may strike to a deeper or denser color after firing, so the red streaks can come back noticeably richer than the unfired sheet suggests. Fire a sample chip first when the final shade matters.
Luminescent coating The Luminescent coating lays a pearl shimmer over the crystal and dark red streaks, drifting through apricot, rose and pale 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 Dark Red side of this blend is sulfur bearing on Wissmach's COE 96 chart. In direct contact with copper bearing colors such as Reactive Blue, Deep Sky Blue, Turquoise Green or Sea Blue, it can form a darker line where the glasses meet. Run a small test tile before committing a project.
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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