HELIOTROPE AND LILAC.
I. These colors being simply medium and light shades of violet, proceed as for the latter color, selecting for heliotrope the bluish brands of methyl violet, and for lilac the red touch mark. The dyebath is acidified with a little tartaric acid, so as to give it a feeble sourish taste and dyeing done at hand-heat until a level color is obtained with very little solution of the dyestuff, and more of it gradually added, while the temperature is raised to nearly boiling, as required for the shade to be produced. Or,
II. Prepare the dyebath simply of cold water acidulated with a little sulphuric acid, add a few drops of the filtered solution of methyl violet (4 B. for heliotrope), and dye to shade without heating. In both cases rinse after dyeing, pass through a bath of raw starch and dye as usual.