434 ENGRAVING IN AQUA TINTA. 



The substance intended to be used for the grain 

 must now be distributed over the plate as equally 

 as possible ; and different methods of performing 

 this essential part of the operation have been used 

 by different engravers, and at different times. 



The most usual way is to tie up some of the 

 powder in a piece of muslin, and strike it against a 

 piece of stick held at a considerable height above 

 the plate; by this, the powder that issues falls 

 gently, and settles equally over the plate. Every 

 one must have observed how uniformly hair-powder 

 settles upon the furniture after the operations of 

 the hair-dresser. This may afford a hint towards 

 the best mode of performing this part of the pro- 

 cess. The powder must fall upon it from a con- 

 siderable height, and there must be a sufficiently 

 large cloud of the dust formed. The plate being 

 covered equally over with the dust, or powder, the 

 operator is next to proceed to fix it upon the plate, 

 by heating it gently, so as to melt the particles. 

 This may be effected by holding under the plate 

 lighted pieces of brown paper, rolled up, and 

 moving them about till every part of the powder is 

 melted ; this will be known by its change of colour, 

 which will turn brownish. It must now be suffered 

 to cool, when it may be examined with a magnifier, 

 and if the grains or particles appear to be uni- 

 formly distributed, it is ready for the next part of 

 the process. 



The design or drawing to be engraved must now 

 be examined, and sucli parts of it as are perfectly 

 wnite are to be remarked. Those corresponding 

 parts of the plate must be covered, or stopped out 

 (as it is called) with turpentine-varnish, diluted with 

 turpentine to a proper consistence to work freely 



