source. Preparation for market requires many steps: First the plants are 

 cut just as they mature, then steeped and allowed to ferment; next the 

 solution containing indigotin is drawn off and the plants are disposed of; 

 the indigotin solution is then subjected to another series of steps. The 

 solution is beaten with paddles to incorporate air into it and to promote 

 oxidation. When oxidation is complete, the indigo material is allowed 

 to settle, the liquid is drawn off, and the mass of indigo, pressed, cut, and 

 dried, is ready for market. 



Early in the 19th century, indigo was often sold in the form of dark blue 

 cubes or cakes called "junks." The quality of these "junks" was a matter 

 of great concern to the professional dyer, for indigo was an expensive dye. 

 If, as one dyer stated, 6}^ pounds of indigo would dye 100 pounds of cloth 

 a full deep blue, the cost of indigo alone per pound of cloth dyed would 

 be more than \4:i, based on the 1831 price of $2.25 per pound (Lynde, p. 8). 

 The cost of indigo and other indigo dye ingredients such as potash, bran, 

 and madder, plus labor costs, added up to a very costly dye operation. 



Opinions differed greatly on which country exported the best grade of 

 indigo. Some dyers considered Bengal (India) indigo the best, claiming 

 that it would color at least 10 percent more cloth than the best Spanish 

 Flote indigo, imported from the Spanish dominions in central America. 

 The criteria by which the 19th-century dyer judged the quality of indigo 

 included: light weight in relation to bulk, smoothness in the fracture, and 

 a bright violet, purple, or bronze hue. 



There was general agreement that the price paid for the indigo should 

 be in proportion to its yield. Thus sometimes buying low-priced indigo 

 with moderate yield could be more profitable than purchasing the highest 

 priced article with proportionately lower yield. 



Since the indigo vat is described in detail in the Dye Recipe section it is 

 only necessary to make some general remarks about indigo dyeing practices 

 in America. 



One learns from early dye manuals that many kinds of blue vats were 

 worked. The main ingredient in all of these was either woad, indigo, or a 

 combination of both. Dyers' opinions differed on the relative merits of 

 woad and indigo; however, it is now known that although the dyeing 

 ingredient indigotin is common to both dyes, it is present in indigo in 

 much greater quantity. 



Indigo is insoluble in water before dyeing, but it is made soluble in the 

 blue vat. Dipping textile material in the dye solution deposits dye in the 

 fibers. When the textile is removed from the dye vat, the air oxidizes the 

 indigo, returning it to its original insoluble form. 



Several combinations of ingredients will help to put indigo into solution. 

 These account for the variety of instructions for making up blue vats that 



17 



