Pl. IV.
69. Biting with Stopping-out.—One Point.—In biting with stopping-out, it is the biting itself, and not the needle, which gives modelling to the etching. In this case, also, one or several points may be used. The simplest manner is that in which only one point is used. The stopping-out, and consequently the biting, is done in large masses. (See [Pl. V.] Fig. 1.)
70. Biting with Stopping-out.—Several Points.—As a very simple example let us take a case in which it is necessary to have certain very closely lined passages in a foreground alongside of very coarse ones. In that case the first, or close, lines must be etched very delicately, while the whole force of the biting must be brought to bear on the latter (see [Pl. IV.] Fig. 2). In the same way the values of two different objects may be equilibrated; by employing close lines slightly bitten in the one case, and spaced lines more deeply bitten in the other. Biting with stopping-out, combined with the work of several points, requires more attention and discernment than any other.
If the first biting is not successful, the plate is revarnished, and the work of repairing and correcting commences.
Summing up the advantages offered by these various means, you will see what results the combination of the work of one or of several points with partial biting may be made to yield, either in giving to objects their various values, their natural color, and their modelling, or in disposing them in space, and thus producing the harmonious gradation of the several distances.
71. Necessity of Experimenting.—If you will now call to mind our preceding operations, and will hold them together with the explanations just given, you will be able to appreciate them in their totality. The necessity of arriving at truth of expression, with nothing to guide you but these rules, which are influenced by a variety of conditions, will compel you to experiment for yourself, with special reference to the combination of the surrounding temperature, the strength of the acid, the number of partial bitings, the pressure of the point, the different thicknesses of the points, and the various kinds of work that can be done with them, on the one hand; and on the other, with regard to the length of the bitings. If you are called upon to imitate a given object very closely, you must proceed rationally, and your work must be accompanied by continual reflection. To familiarize yourself with these delicate operations, you must experiment for yourself; don't complain if you spoil a few plates; you will learn something by your failures, as your experience in one case will teach you what to do in others. Self-acquired experience is of all teachers the best.
72. Various other Methods of Biting.—The two preceding methods, which, in a general way, comprehend the rules of biting, do not exclude other particular methods of a similar nature. Thus, it may be well sometimes to etch at first only the simple outline, biting it in more or less vigorously, according to the nature of the case ([Pl. IV.] Fig. 3); and then, having revarnished and resmoked the plate, to elaborate the drawing by going over it either in some parts only or throughout the whole. Rembrandt often pursued this course; and we may follow the several stages of his work by studying the various states of his plates. We see that he took great pains to work out some part of his subject very carefully, without touching the other parts; he then took a proof, and afterwards went over the same part with finer lines, and passed on to the other parts, treating them according to the effect which he desired to reach.
This method is often imitated; it is employed when it is necessary to lay a shadow over a passage full of detail, as, for instance, in architectural subjects, in the execution of which it is easier, and tends to avoid confusion, to fix the lines of the design first, and then, having laid the ground a second time, to add the shadows. (See [Pl. IV.] Fig. 4.)