ENGRAVING AND TRIMMING.
After etching, the plate is passed to the engraver for the removal of any black spots, for the making of white lines, and for putting in high lights, etc. It is in the engraver's power to improve the result greatly where the requisite time and labour is permissible. A good plate, how by lightening parts which are too dark. This is accomplished by " stopping-out " the parts that do not require treatment with varnish or other resist, and re-etch ing the desired portion. Obviously this requires a certain amount of artistic taste. Vignetting is also clone on the block, when necessary, by stopping-out the image to within about three-quarters of an inch of the required boundary, carefully softening or stippling the varnish at the edges with a hog-hair brush. The plate is then etched for one minute, then dried, and the varnishing and softening repeated, bring ing the edge of the varnish a little nearer to the boundary of the vignette. Another minute's immersion in the etching bath is now given, followed by a repetition of the ever, should require but little touching up. A light part of the block can often be made to print darker by rubbing with a highly polished steel burnisher (Fig. 910).
Roulettes (Figs. 911 to 915) are employed for lightening dark places, by stippling the plate with tiny holes. These are also made with lines instead of dots, for breaking up line work and softening hard edges. The next step is to bevel the margins of the metal plates, so that the nails used in fastening them to the wood blocks may lie below the surface. In small establish ments this is accomplished with a shoot plane working on an iron bed-plate (Fig.
916). Two planes are supplied with this appliance, one for trimming the wood block and the other for bevelling the metal. Where much work is done, special machinery, driven by power of some description, is employed for these pur poses. In Royle's " lining beveller," an elaborate arrangement of this kind, pro vision is made not only for bevelling the plate but for mechanically engraving black or white lines, of any desired spacing and width, round the margin of the picture.