This section is from the "A Complete Dictionary of Dry Goods" book, by George S. Cole. Also available from Amazon: A complete dictionary of dry goods and history of silk, cotton, linen, wool and other fibrous substances,: Including a full explanation of the modern processes ... together with various useful tables.
Bloom. A term applied to velvets, when by dyeing they are said to glow with a warm color, or luster. Dyers claim that the most important branch of black-dyeing upon cotton goods, is that empolyed for cotton velvets, in which it is desired to produce a rich lustrous effect; the process is long, tedious and uncertain, consisting of successive applications of sumac, acetate of iron, logwood and fustic — the end chiefly aimed at being the production of a black, with a blush or violet bloom.