Wissmach Crystal/Oyster Pearl (color code 96-74) is a Prisma blend in COE 96 kiln glass, clear glass swirled with pearl white in a 3mm sheet, tested for fusing compatibility.
Appearance Wisps and veils of pearl white curl through a clear ground like smoke caught in ice, denser in some passages and thinning to a breath in others. Crystal is named first, so the clear dominates, letting light through wherever the pearl thins. The streaking is unique to each sheet, so no two are identical.
Striking Like Wissmach's other Prisma colors, this blend may strike to a slightly deeper or denser look after firing, with the pearl passages coming out a little richer. Fire a sample chip if the exact effect matters.
Working notes Wissmach’s recommended full fuse schedule for a 6mm project made from two 3mm layers: heat at 300 degrees F per hour to 1225 F and hold 30 minutes, then 600 per hour to 1460 F with a 10 minute hold, cool as fast as the kiln allows to 960 F and hold 1 hour, then 100 per hour down to 700 F. These numbers come from Wissmach’s current published firing guidance. They are guidelines, not guarantees. Kilns differ, so fire a small test piece first.
Reactions The Oyster Pearl in this blend makes it 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. 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 with a Luminescent coating .
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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