Black Opalescent 000100
Although termed an opal due to its almost total lack of light transmission, this is (in terms of its composition) actually a transparent glass.
Low viscosity. Will flow sooner and more than other glasses. In very thin sections the color may vary from reddish/gray to bluish/gray.
Torch: 000100-0576 remains black except in extremely thin applications, when it may become dark gray. It is a soft glass. Beware of heating the glass so much that it bleeds and webs out over other glasses‚ or use this quality as a design element. Consider using 000101-0576, Stiff Black for a crisper appearance.
Kiln: Working properties and kilnformed characteristics are consistent with sheet glass. See sheet glass notes for this style.