Sometimes a little indigo blue or smalt is also added, when a peculiar bloom colour is desired.
The inferior kinds of smalt are occasionally adulterated with chalk.
The portion of Arsenic that is thus fixed vitrifies with the colouring matter, and enters into the composition of the smalt.
This blue is distinguished from smalt by dissolving in acetic acid.
Ultimately the goods are mill-washed, blued with smalt and dried.
Zaffre is the roasted mineral ground with sand, while smalt, a term used more frequently, is the fused mixture with sand.
Starch is used along with smalt, or stone-blue, to stiffen and clear linen.
The smalt is usually composed of one part of calcined cobalt, fused with two parts of powder of flint and one of pot-ash.
In this trial the glass of Borax will be nearly of the same colour as the true glass, or smalt, made with the same Cobalt.
Authorities state that these may be formed from bright Prussian blue or verditer glazed over with Prussian blue or of smalt.