Enamel, Red

Prep. 1. ‘Paste’ or ‘flux,’ coloured with the red oxide or protoxide of copper. Should the colour pa into the green or brown, from the partial peroxidation of the copper, from the heat being raised too high, the red colour may be restored by the addition of any carbonaceous matter, as tallow, or charcoal. 2. By tinging the gla or ‘flux’ with the oxide or salts of gold, or with the purple precipitate of ca ius. These substances produce shades of red, inclining to crimson or purple of the most exquisite hue. The enamel often comes from the fire quite colourle , and afterwards receives its rich hue at the lamp. 3. (Wynn.) Sulphate of iron (calcined dark), 1 part; a mixture of 6 parts of ‘flux’ (No. 5), and 1 of colcothar, 3 parts. Dark red. 4. (Wynn.) Red sulphate of iron, 2 parts; ‘flux’ (No. 1), 6 parts; white lead, 3 parts. Light red.