286 ENGRAVING 



very correct outline of the subject is made -with a black-load pencil on a piece of thin 

 hard paper : fasten the tracing, or drawing, at the top edge, with its face downwards, 

 on to the etching-ground, with a piece of banking-wax, described hereafter, and by 

 passing it through a printing-press such as is used by plate printers, to whom it 

 should bo taken tho drawing is transferred to the ground. The bridge being laid 

 over thd plate, the process of etching may now be commenced ; tho points, or needles, 

 which are used to complete tho design, remove the ground from the metal wherever 

 they pass, and expose tho latter to tho action of tho acid during the process of what 

 is termed biting-in. Tho needles with tho most tapering points should be used for the 

 skies and distances, changing them for others for tho foreground, which generally re- 

 quires broader and deeper lines. Any error that has been made may bo remedied by 

 covering tho part evenly with the etching-ground mollified by spirits of turpentine, 

 using a camol's-hair pencil for the purpose ; and, when dry, tho lines may bo re- 

 etched through it. 



Tho next operation is that of biting-in, performed thus : A wall or border of bank- 

 ing-wax is put round the edge of the plate : this wax, called sometimes bordering -wax, 

 is made by melting over a slow fire, in a glazed pot, two parts of Burgundy pitch, and 

 one of bees' -wax, to which is added when melted, a gill of sweet oil ; when cold it is 

 quite hard, but by immersion in warm water it becomes soft and ductile, and must be 

 applied in this state : it will adhere to the metal by being firmly pressed down with 

 the hand: the object in thus banking up the plate is to prevent the escape of tho 

 acid which is to bo applied; but a spout or gutter must be left at one corner to pour 

 off the liquid when necessary. Mr. Fielding, to whose work on tho art of engraving 

 wo are indebted for some of the practical hints here adduced, availing ourselves, 

 however, of tho improvements introduced into modern practice, recommends the 

 following mixture as the best : ' Procure some strong nitric acid, and then mix, in 

 a wide-mouthed bottle, one part of the acid, with five parts of water, adding to it a 

 small quantity of sal-ammoniac, in the proportion of the size of a hazel-nut to one 

 pint of acid, when mixed for biting. The advantage of using the sal-ammoniac is, 

 that it has the peculiar property of causing the aqua-fortis to bite more directly down- 

 wards, and less laterally, by which means lines laid very closely together are less 

 liable to run into each other, nor does the ground so readily break up.' When tho 

 mixture is cool for tho acid becomes warm when first mixed with water pour it 

 on the plate, and let it continue there till tho more delicate lines are presumed to bo 

 corroded to a sufficient depth ; this will probably be in about a quarter of an hour ; 

 sweep off the bubbles as they appear on the plate, with a caniel's-haii 1 pencil, or a 

 feather ; then pour off the acid through the gutter at the corner, wash the plate with 

 warm water, and leave it to dry. Next, cover those parts which are sufficiently 

 bitten in with Brunswick black, applying it with a camel's-hair pencil, and leave it to 

 dry ; again put on the acid, and let it remain twenty minutes or half an hour, to give 

 the next degree of depth required ; and repeat this process of stopping out and bitiiig 

 in, until the requisite depths are all attained : three bilings are generally enough for a 

 painter's etching. The work is now complete, unless the graver is to be used upon it, 

 and the banking-wax may be removed, by slightly warming tho margin of tho plate ; 

 and, finally, wash tho latter with a soft rag dipped in spirits of turpentine, and 

 rubbing it with olive-oil. If, when the plate is cleaned, the engraver finds that tho 

 acid has acted as ho wishes, ho has secured what is technically termed ' a good 

 bite.' 



Steel plates require another method of biting-in, on account of their extreme hard- 

 ness, and liability to rust ; the mode just described is applicable only to copper, 

 tho metal generally used by painters for their etchings. For steel plates mix 

 together 



Parta 



Pyroligneous acid 1 



Nitric acid 1 



Water 3 



This mixture should not be allowed to remain on above a minute; let it bo washed 

 off at once, and never use the same water twice ; the plate must bo set up on its nl^o, 

 and dried as quickly as possible to avoid rust : tho acid may be strengthened where 

 a stronger tint is required. 



Re-biting, a process frequently adopted to increase the depth of tint where it is 

 required, or to repair any portion of a plato that haw IXTM worn by printing or acci- 

 dentally injured, is thus performed. Tho plate must be thoroughly cleaned, all traces 

 of grease removed, by washing it with spirits of turpentine and potass, and polished 

 with whiting ; it is then, when warmed over a charcoal fire or with lighted paper, 

 ready for receiving the ground ; this is laid by using a dabbor charged with etching- 

 ground, and carefully dabbing tho surface ; by this means the surface of the plate 



