Wissmach Crystal/ Reactive Blue (color code 96-75) is a Prisma blend in COE 96 kiln glass, icy blue streaks feathering through clear crystal in a 3mm sheet, tested for fusing compatibility.
Appearance Feathered vertical currents of sky blue pull through a milky crystal ground, like ice breaking up in moving water, with the streaks thinning to wisps in some passages and pooling denser in others. 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 crystal leads here with the blue threading through it. The streaking is unique to each sheet, so no two are identical.
Striking As with the rest of Wissmach's Opaque and Prisma palette, expect some strike: the fired sheet often lands a bit deeper and denser than the glass you cut. Fire a test chip if you need to hit an exact shade.
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 copper on Wissmach's COE 96 chart through its Reactive Blue component. Fired in direct contact with sulfur bearing colors such as String of Pearls, Oyster Pearl, Gold Tone, Honey or the red and orange family, it can form a darker copper sulfide line where the glasses touch. Results vary by batch and combination, so test fire the pairing first.
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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