438 ENGRAVING IN AQUA TINTA. 



a-fresh. The plate must also be previously cleaned, 

 with the greatest possible care, with a rag and 

 whiting, as the smallest stain or particle of grease 

 produces a streak or blemish in the grain. All 

 these attentions are absolutely necessary to produce 

 a tolerably regular grain j and, after every thing 

 that can be done by the most exprienced artists, 

 still there is much uncertainty in the process. They 

 are sometimes obliged to lay on the grains several 

 times, before they procure one sufficiently regular. 

 The same proportions of materials do not always 

 produce the same effect, as it depends in some 

 degree on their qualities: and it is even materially 

 altered by the weather. These difficulties are not 

 to be surmounted but by a great deal of experience ; 

 aad those who are daily in the habit of practising 

 the art are frequently' liable to the rriost unaccount- 

 able accidents. Indeed, it is much to be lamented, 

 that so elegant and useful a process should be so 

 extremely delicate and uncertain. 



It being necessary to hold the plate in a slanting 

 direction, in order to drain off the superfluous fluid, 

 there will naturally be a greater body of the liquid 

 at the bottom than at the top of the plate. On this 

 account, a grain laid in this way is always coarser 

 at the side of the plate that was held lowermost. 

 The most usual way is, to keep the coarsest side for 

 the fore-ground, that being generally the part 

 which has the deepest shadows. In large land- 

 scapes, sometimes various parts are laid with dif- 

 ferent grains, according to the nature of the subject. 



The finer the grain is, the more nearly does the 

 impression resemble Indian-ink, and the fitter it is for 

 imitating drawings: but very fine grains have several 

 disadvantages; for they are apt to come off before 

 the aqua fortis has lain on long enough to produce 



