COOXR
Cuprous oxide — a red powder · The most concentrated of the three copper additions we carry · Nine parts stand in for ten parts of black copper oxide · In oxidation it finishes the same green as black copper oxide · Bought mainly for reduction and raku work · Floats on the water instead of mixing in — a drop or two of detergent disperses it · Fluxes strongly, and volatile above about cone 8
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Red copper oxide is cuprous oxide, and it carries more copper per gram than any other copper addition we stock. It colours glazes and slips as the other two copper additions do.
Red copper oxide is cuprous oxide, and it is the most concentrated of the three copper additions we carry — more copper by weight than black copper oxide, and more again than copper carbonate. Nine parts of it stand in for ten parts of the black oxide. Reduction and raku are what it is usually bought for, though copper carbonate is the finer grind and appears in more copper red recipes than this does, so the choice between them comes down to grind and price rather than colour. In the bucket it behaves differently from the other two: the powder floats on the water instead of mixing in. A drop or two of detergent breaks the surface tension and it disperses. Like all copper it fluxes strongly and goes volatile above about cone 8.
