A Treatise on Etching

by Maxime Lalanne

Nothing, indeed, is simpler. You understand that the background, which is bitten in quite lightly, must show very delicate lines, while in the middle distance and in the foreground the lines are enlarged by the action of successive bitings. When it comes to the printing, the quantity of ink received by these various lines will be in proportion to the values which you desired to obtain, and in the proofs you will have a variety of lighter or stronger tones, giving you the needed gradations in the various distances. It follows from this that, if you had worked too sparingly on the distances which receive only a light biting, you could not have reached the value of the tone which you strove to get, and if you had worked too closely on those parts which require continued biting, you would have had a black and indistinct tone, because the lines, which are enlarged by the acid, and consequently keep approaching one another, would finally have run together into one confused mass, producing what in French is called a crevé (blotch).

In an etching the space between the lines must be made to serve a purpose; for the paper seen between the black strokes gives delicacy, lightness, and transparency of tone.

37. The Crevé.—Its Advantages and Disadvantages.—In very skilled hands the crevé is a means of effect. If you wish to obtain great depth in a group of trees, in a wall, in very deep shadows, you will risk nothing by intermingling your lines picturesquely and biting them vigorously. In this way you can produce tones of velvety softness, and at the same time of extraordinary vigor. Similarly, you may strike a fine note by means of running together several lines which, if sufficiently bitten, will form but a single broad one of great solidity and power. It is, indeed, only the exaggeration of this expedient, which, by unduly enlarging the limits of the broad line just spoken of, and thus producing a large and deep surface between them, constitutes the crevé properly so called; the printing ink has no hold in this flat hollow, and a gray spot in the proof is the result. I have warned you of the accident; later on you shall hear something of the remedy. We will now continue our biting. Plunge your plate into the bath again, if you please.

38. Means of ascertaining the Depth of the Lines.—“My dear sir, I see that my drawing turns black; it disappears almost entirely, and is lost in the color of the ground.[9] I am quite perplexed. My mind endeavors to penetrate beneath this varnish, so as to be able to witness the mysterious birth of my œuvre. See these violent ebullitions! What do you think of them?”

Let them go on a moment longer, and then withdraw your plate. We have now arrived at a point where the eye cannot judge of the work of the acid as easily as before; henceforth we must, therefore, examine the depth of our bitings by uncovering a single line, as, for instance, this one here in the ground. Or we may even lay bare, by the aid of spirits of turpentine, a part of the foreground, provided, however, that we must not forget to cover it again with the brush. This will give us an idea of the total effect so far produced by the biting, and we can then regulate the partial bitings which are still to follow, either by a comparison of the time employed on those that have gone before, or by the intensity of the ebullitions, the action of which on the copper we have already studied. You perceive that, while it is difficult to fix a standard of time for the bitings at the beginning of the operation, it is yet possible to calculate those to come by what we have so far done.

39. The Rules which govern the Biting are subordinated to various Causes.—In reality, it is impossible to establish fixed rules for the biting, for the following reasons:—

1. Owing to the varying intensity of the stroke of the needle. The etcher who confines himself to gently baring his copper must bite longer than he who attacks his plate more vigorously, and therefore exposes it more to the action of the acid.

2. Owing to the different quality of the plates.

3. Owing to the difference in temperature of the surrounding air:—of this we have before spoken.

4. Owing to difference of strength in the acid, as it is impossible always to have it of absolutely the same number of degrees. At 15° to 18° the biting is gentle and slow; at 20° it is moderate; at 22° to 24° it becomes more rapid. It would be dangerous to employ a still higher degree for the complete biting-in of a plate, especially in the lighter parts.