ENGRAVING IN AQUA TINTA. 437 



A grain is thus produced with the greatest ease, 

 which is extremely regular and beautiful, and 

 much superior for most purposes to that produced 

 by the former method. After the grain is formed, 

 every part of the process is conducted in the same 

 manner as above described. 



Having thus given a general idea of the art, we 

 shall mention some particulars necessary to be 

 attended to, in order to ensure success in the oper- 

 ation. The spirits of wine used for the solution, 

 must be highly rectified, and of the best quality. 

 What is sold in the shops generally contains cam- 

 phor, which would entirely spoil the grain. Resin, 

 Burgundy-pitch, and gum mastich, when dissolved 

 in spirits of wine, produce grains of a different 

 appearance and figure, and are sorhetimes used 

 separately, and sometimes mixed in different pro- 

 portions, according to the taste of the artist, some 

 using one substance, and some another. In order 

 to produce a coarser or finer grain, it necessary to 

 use a greater or smaller quantity of resin; and to 

 ascertain the proper proportions, several spare pieces 

 of copper must be provided, on which the liquid 

 may be poured, and the grain examined, before it is 

 applied to the plate to be engraved. After the 

 solution is made, it must stand still and undisturbed 

 for a day or two, till all the impurities of the resin 

 have settled to the bottom, and the fluid is quite 

 pellucid. No other method of freeing it from those 

 impurities has been found to answer ; straining it 

 through linen or muslin, only fills it with hairs, 

 which are ruinous to the grain. The room in which 

 the liquid is poured on the plate must be perfectly 

 still and free from dust, which, whenever it falls on 

 the plate while wet, causes a white spot, which it is 

 impossible to remove without laying the grain 



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