Wissmach Sky Blue Opalescent with Luminescent coating (base color code 96-71) is COE 96 kiln glass, a pale sky blue opaque 3mm sheet with an iridescent surface, tested for fusing compatibility.
Appearance The coating turns the pale sky blue base silvery and pearlescent, with faint horizontal bands of aqua, lavender and pale gold ghosting across the surface as the viewing angle changes. The shimmer shows in ordinary room light, no special lighting needed. As an opaque the base blocks light, so the effect reads the same on a tabletop as it does in a window.
Striking Wissmach flags its Opaque and Prisma colors as possible strikers, deepening or densening with heat. The fired blue will usually read a little richer than the sheet, so fire a sample chip when the shade matters.
Luminescent coating The Luminescent coating lays a silvery mother of pearl shimmer over the sky blue base, drifting through aqua, lavender 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 base glass is Sky Blue, 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 Honey, it can form a darker reaction line at the contact edge. 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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