This sulphur-bearing glass may react with gold-bearing lead (001311, 001215, 000301, 000305) and copper (001116, 001408, 001417, 000144, 000145, 000146) glasses to create dark interface (lead sulphide, copper sulphide). See our chart Reactive Potential of Bullseye Glasses for more information.

Very viscous; will flow later and less than other glasses. Generally more sensitive to heat-history and more likely to show variation in colour after fusing than many opals. When fired on edge, a clear distinction between outside and interior surfaces is commonly seen (a variation used by designers). This glass may become increasingly white with repeated firings. Consider using glass from the same batch for a given project.

Dense White (000313) Reaction Note: The fired surface of French Vanilla does not react as readily to lead-bearing Dense White (000313), compared to firing the same combination in a single firing (using glass that has not previously been fired). However, this combination does react when re-fired to a full fuse. The fired and sandblasted surface of French Vanilla will react more readily with Dense White in a secondary full fuse. This provides a design opportunity with the contrast between the sandblasted areas (which do react) and any masked-off areas (which do not). This contrast is sensitive to further heat work as reactions will begin to develop as low as 1150°F. Our tests show that continued heat work in this firing will develop a stronger reaction in the masked off (fired surface) areas. If designing with this characteristic, further testing is recommended.

Copper-Bearing Glasses Reaction Note: French Vanilla will react to varying degrees with glasses containing copper. The sample below shows copper-bearing Turquoise Blue (000116) in various forms (-08, -01, -02, -03, -30), fired over French Vanilla (000137, top half), with each then layered over with White (000113, bottom half). The area of interface and effects vary between French Vanilla and Turquoise Blue. The White does not react with either.