The graver is the customary and fundamental tool of what is properly called “line-engraving.” Although it is not absolutely necessary in the species of etching which we are studying, there are cases, nevertheless, in which it can be used to advantage, but always as an auxiliary only.
If, for instance, you desire to give force to a deeply bitten but grayish and dull passage, or to a flat tint which looks monotonous, a few resolute and irregular touches with the graver will do wonders, and will add warmth and color. A few isolated lines with the graver give freshness to a muddy, broken, or foxy tint, without increasing its value.
The graver may also be employed in patching deeply bitten passages.
The graver, of a rectangular form, with an angular cutting edge, is applied almost horizontally on the bare copper; its handle, rounded above, flat below, is held in the palm of the hand; the index finger presses on the steel bar; it is pushed forward, and easily enters the metal: the degree of pressure applied, and the angle which it makes with the plate, produces the difference in the engraved lines. The color obtained by the burin is deeper than that obtained by biting, as it cuts more deeply into the copper. If extensively used in an etching, the work executed by the graver contrasts rather unpleasantly with the quality of the etched work, as its lines are extremely clear cut. To get rid of this inequality, it is sufficient to rebite the passages in question very slightly, which gives to the burin-lines the appearance of etched lines.
In short: use the graver with great circumspection, as its application to works of the needle is a very delicate matter, and gives to an etching a character different from that which we are striving for. It seems to me that to employ it on a free etching, done on the spur of the moment, would be like throwing a phrase from Bossuet into the midst of a lively conversation.[17]
76. Sandpaper.—As regards other mechanical means, be distrustful of tints obtained by rubbing the copper with sandpaper; these tints generally show in the proof as muddy spots, and are wanting in freshness. Avoid the process, because of its difficulty of application. Only a very skilful engraver can put it to good uses.
77. Sulphur Tints.—I shall be less afraid to see you make use of flowers of sulphur for the purpose of harmonizing or increasing the weight of a tint. The sulphur is mixed with oil, so as to form a homogeneous paste thick enough to be laid on with a brush.
By the action of these two substances the polish on the plate is destroyed, and the result in printing is a fresh and soft tint, which blends agreeably with the work of the needle.
Differences in value are easily obtained by allowing the sulphur to remain on the plate for a greater or less period of time. This species of biting acts more readily in hot weather; a few minutes are sufficient to produce a firm tint. In cold weather relatively more time is needed. The corrosions produced in this way have quite a dark appearance on the plate, but they produce much lighter tints in printing. If you are not satisfied with the result obtained, you can rub it out with charcoal, as the copper is corroded only quite superficially.
Owing to this extreme slightness of biting, the burnisher may also be used to reduce any parts which are to stand out white.