170 DYES 



with woolen and silk material and yet are fairly satisfactory 

 when applied to cotton and linen fabrics. Then, too, a dye 

 which will color silk may not have any effect on wool, in spite 

 of the fact that wool, like silk, is an animal fiber ; and certain 

 dyestuffs to which cotton responds most beautifully are abso- 

 lutely without effect on linen. 



The nature of the material to be dyed determines the color- 

 ing matter to be used ; in dyeing establishments a careful ex- 

 amination is made of all textiles received for dyeing, and the 

 particular dyestuffs are then applied which long experience 

 has shown to be best suited to the material in question. Where 

 " mixed goods," such as silk and wool, or cotton and wool, are 

 concerned, the problem is a difficult one, and the countless 

 varieties of gorgeously colored mixed materials give evidence 

 of high perfection in the art of dyeing and weaving. 



Housewives who wish to do successful home dyeing should 

 therefore not purchase dyes indiscriminately, but should select 

 the kind best suited to the material, because the coloring 

 principle which will remake a silk waist may utterly ruin a 

 woolen skirt or a linen suit. 



Indirect dyeing. The varied uses to which dyed articles are 

 put make fastness of color absolutely necessary. A shirt, for 

 example, must not be discolored by perspiration, nor a waist 

 faded by washing, nor a carpet dulled by sweeping with a 

 dampened broom. In order to insure permanency of dyes, an 

 indirect method was originated which consisted of adding tc 

 the fibers a chemical capable of acting upon the dye and 

 forming with it a colored compound insoluble in water, and 

 hence " safe." For example, cotton material dyed directly 

 in logwood solution has almost no value, but if it is soaked in 

 a solution of oxalic acid and alum until it becomes saturated 

 with the chemicals, and is then transferred to a logwood 

 bath, the color acquired is fast and beautiful. 



