Wissmach Reactive Blue/ Oyster Pearl (color code 96-37) is a Prisma blend in COE 96 kiln glass, soft blue and warm pearl streaks in a 3mm sheet, tested for fusing compatibility.
Appearance Vertical ribbons of powdery blue run beside warm sand and ivory pearl bands, with the soft, cloudy depth that comes from blending an opaque into the mix. 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 blue leads here with the pearl weaving through it. The streaking is unique to each sheet, so no two are identical.
Striking Wissmach notes that its Opaque and Prisma colors may strike to a deeper or denser color after firing, so expect the fired sheet to come out a little richer than it looks unfired.
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 This blend carries both markers on Wissmach’s COE 96 chart: Reactive Blue brings copper and Oyster Pearl brings sulfur. In direct contact with neighbors from either family it can form darker reaction lines where the glasses touch. Results vary by batch, temperature and combination, so test fire the pairing 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 The reverse blend, with pearl leading, is Oyster Pearl/ Reactive Blue .
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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