1835.] 



Calico-Printing . 



329 



clay, be printed upon white cloth, the piece may be im- 

 mersed in the blue vat without any of the indigo attach- 

 ing itself to the parts of the cloth so printed. If the 

 piece of cloth be then dunged and dyed in the usual way, 

 a red is produced on a pale blue ground. The same mor- 

 dant, with the addition of acetate of iron, gives a chocolate 

 colour. 



Let us now explain how the white portion in the speci- 

 men of printed cloth before us has been preserved from 

 the dye. A preparation called neutral paste is employed in 

 this style of work, to defend the cloth against both the 

 red and chocolate and the blue. It is a mixture of lime- 

 juice and sulphate of copper. If this mixture remains 

 upon the cloth longer than a few days, a portion of the 

 oxide of copper attaches itself so firmly to the cloth that 

 no washing is capable of removing it. And this portion 

 of copper attracts a portion of the madder in dyeing, and 

 tinges the part of the cloth intended to be white, of a pale 

 brownish red. 



In the specimen before us, all that is now bronze, yellow 

 and pink, was originally printed with the white ; the three 

 colours given by catechu, Persian berries, and Brazil pink, 

 being a subsequent application. The green is the result of 

 berry-yellow on the blue, and the orange of the same colour 

 on the pink. 



12. Pigment Printing, 



This is a species of printing which has been lately in- 

 troduced for dresses which are not intended to be washed. 

 The colours are the same that are used for painting or 



