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Tyrian purple is a pigment made from the mucus of several species of Murex snail. Production of Tyrian purple for use as a fabric dye began as early as 1200 BC by the Phoenicians, and was continued by the Greeks and Romans until 1453 AD, with the fall of Constantinople.
BASF developed a commercially feasible manufacturing process that was in use by 1897, at which time 19,000 tons of indigo were being produced from plant sources. This had dropped to 1,000 tons by 1914 and continued to contract.
The Verneuil method (or Verneuil process or Verneuil technique), also called flame fusion, was the first commercially successful method of manufacturing synthetic gemstones, developed in the late 1883 by the French chemist Auguste Verneuil.
The hectograph, gelatin duplicator or jellygraph is a printing process that involves transfer of an original, prepared with special inks, to a pan of gelatin or a gelatin pad pulled tight on a metal frame.
Manganese is one of the oldest glass additives, and purple manganese glass was used since early Egyptian history. Manganese dioxide, which is black, is used to remove the green color from the glass; in a very slow process this is converted to sodium permanganate, a dark purple compound.
They satisfied themselves that they might be able to scale up production of the purple substance and commercialise it as a dye, which they called mauveine. Their initial experiments indicated that it dyed silk in a way which was stable when washed or exposed to light.
Process manufacturing is common in the food, beverage, chemical, pharmaceutical, nutraceutical, consumer packaged goods, cannabis, and biotechnology industries. In process manufacturing, the relevant factors are ingredients, not parts; formulas, not bills of materials; and bulk materials rather than individual units.
In the second step, air or sulfur dioxide at 350 to 450 °C is used to oxidize sulfide in the intermediate product to S 2 and S n chromophore molecules, resulting in the blue (or purple, pink or red) pigment. The mixture is heated in a kiln, sometimes in brick-sized amounts.
The CMYK color model (also known as process color, or four color) is a subtractive color model, based on the CMY color model, used in color printing, and is also used to describe the printing process itself.
In medieval Europe, purple, violet, murrey and similar colors were produced by dyeing wool with woad or indigo in the fleece and then piece-dyeing the woven cloth with red dyes, either the common madder or the luxury dyes kermes and cochineal. Madder could also produce purples when used with alum.