FINISHING THE PLATE.
43. Omissions.—Insufficiency of the Work so far done.—The result you have obtained, I tell my pupil, as he shows a proof of the first state of his plate to me, is not final. Your work needs a few retouches and slight modifications, not counting the little irregularities which I had foreseen, and which it will be easy enough to repair. We will proceed in order. (See [Pl. Ia]). To commence with, here are certain parts which are sufficiently bitten, and which, nevertheless, are indecisive in tone, and do not hold their place. I allude to the columns and to the trees in the further distance; one feels that there is something wanting there, which must be added. You must, therefore, re-cover your plate, in the manner already known to you, either with transparent ground, or with ordinary etching-ground, just as if the plate had never yet been touched by the needle.
44. Transparent Ground for Retouching.—The white or transparent ground or varnish[11] admirably allows all previous work to show through. It is preferred to the ordinary ground for working over parts that have been insufficiently bitten, on account of its transparency, which leaves even the finest lines visible, while under the ordinary ground these lines might be lost entirely. It will be an easy matter for you to combine the new work with the old; the very slight shadow thrown on the copper by the transparent ground will give a blackish appearance to your lines, which may serve as a guide to you, and, with your proof before your eyes, you will readily succeed in finding the places which need retouching. To make assurance doubly sure, you can indicate the retouches on your proof with a lead-pencil.
The transparent ground has occasionally been found to crack and scale off, when left in the bath for a long while, or when strong acid is used. But as you are only going to use it for light and, consequently, short biting, you need not fear this danger. Another inconvenience, which may easily be prevented, consists in the presence of small bubbles of air, which appear on the varnish as soon as it begins to melt. Heat the plate just to the proper point of melting, and dab it vigorously for some length of time, until the varnish cools; then hold the back of the plate flat to the fire; the varnish melts again, and the rest of the bubbles disappear. If some of them should prove to be obstinate, cover them very lightly with the brush, as otherwise the acid will penetrate through the passages thus left open, and will make little holes in the copper, which, on removing the varnish, will cause an unpleasant surprise. You shall hear more of this further on.
45. Ordinary Ground used for Retouching.—Biting the Retouches.—Ordinary etching-ground, such as we used in the first instance, does not show the work previously done as well as the transparent ground, but the later additions are seen all the better on it. It may be used in its natural state, or it may be smoked. It is preferable to the transparent varnish, whenever the work already achieved is deeply bitten, and hence easily seen.
In the present case my advice is that you use the ordinary ground. Having made your retouches, introduce your plate into the bath, and proceed as before, by partial biting, endeavoring, as much as possible, to obtain the same intensity of tone. These additions, thus bitten by themselves, will mingle with the lines previously drawn, and now protected by the varnish.
It is hardly possible to judge of the additions, especially on transparent varnish, until they have been bitten in. But, if you should then find that you have not yet reached your point, you can revarnish the plate once more, and complete the parts that appear to be unfinished.
I must also call your attention to the fact, that all lines drawn on transparent ground seem to thicken most singularly, as soon as the acid begins to work. But do not let that deceive you.
Now look at this spot in the immediate foreground ([Pl. Ia]), which has a somewhat coarse appearance. It is much softer in the original (represented by [Pl. II.]). You must add a few lines, and must bite them rather lightly; they will mingle agreeably with the energetic lines of the first state. You may put the large trees through the same process, and you will find that they gain in lightness by it. Later on, when you have acquired more experience, you will occasionally find it handy to make these additions between two bitings. You will thus reach the desired result without the necessity of regrounding your plate.
Sometimes, when using strong acid for these retouches, the lines first drawn are also attacked by the liquid. In that case, stop the biting immediately, and rest contented with what you have got. It is not difficult to understand why these revarnished lines should commence to bite again, more especially if they are deep: the acid, finding the edges of the lines (which are sharp and angular, and therefore do not offer much hold to the varnish) but indifferently protected, attacks them, without going into their depths. The ravages thus committed along the edges of the lines may be quite disastrous; and it is well, therefore, whenever you revarnish a plate, to give additional protection to those parts which are not to be retouched, by going over them with stopping-out varnish.