COLOR DESIGNS IN CLOTH 171 



This method of indirect dyeing is known as the mordanting 

 process : it consists of saturating the fabric to be dyed with 

 chemicals which will unite with the coloring matter to form 

 compounds unaffected by water. The chemicals are called 

 mordants. This process is chiefly used with cotton goods. 



How variety of color is secured. The color which is fixed 

 on the fabric as a result of chemical action between mordant 

 and dye is frequently very different from that of the dye itself. 

 Logwood dye when used alone produces a reddish brown color 

 of no value for either beauty or permanence ; but if the fabric 

 to be dyed is first mordanted with a solution of alum and oxalic 

 acid and is then immersed in a logwood bath, it acquires a 

 beautiful blue color. 



Moreover, since the color acquired depends upon the mor- 

 dant as well as upon the dye, it is often possible to obtain a 

 wide range of colors by varying the mordant used, the dye 

 remaining the same. Fabrics immersed directly in alizarin 

 acquire a reddish yellow tint. When, however, they are mor- 

 danted with certain aluminium compounds they acquire a bril- 

 liant Turkey red ; when mordanted with chromium compounds, 

 a maroon ; and when mordanted with iron compounds, the 

 various shades of purple, lilac, and violet. 



Color designs in cloth. It is thought that the earliest 

 attempts at making " fancy materials " consisted in painting 

 designs on a fabric by means of a brush. In more recent 

 times the design was cut in relief on hard wood, the relief being 

 then daubed with coloring matter and applied by hand to suc- 

 cessive portions of the cloth. 



The most modern method of design making is that of machine 

 or roller printing. In this, the relief blocks are replaced by en- 

 graved copper rolls which rotate continuously and in the course 

 of their rotation automatically receive coloring matter on the 

 engraved portion. The cloth to be printed is drawn uniformly 



