"They all, without exception, are covered with a varnish or glazing of a dark colour, but not in all of the same tint; in some, it has a greenish hue, and a lustre of a metallic appearance; this is most striking in those found near Nola. In many, the varnish is of a brown black, like asphaltum.
"The vases may be ranked in four classes.
"1. Those covered with varnish without ornament or painting of any kind.
"2. Those which bear on the natural ground of the ware, figures in black varnish.
"3. Those whose figures are left in red, the vase being covered with varnish.
"4. Vases covered entirely with varnish, on which ornaments are painted in colours.
"Of the first sort it will be necessary to say but little. Many of the most exquisitely formed Nolan vases are of this sort. The varnish appears to have been laid on while the vase was on the lathe. The parallel strokes visible on the surface of the varnish, and its extreme equality of tint, prove this. No better mode can be devised for varnishing, except dipping the ware into the liquid varnish; and this was not done in these vases, as the varnish never covers the hollow of the foot, nor descends deep within the neck. I cannot at all say whether the vase was varnished while yet wet, or first suffered to dry, or even baked a first time, as is the process in much of our common modern glazed earthenware.
"The second sort bear in general marks of the most remote antiquity. The figures are universally of a stiff and meagre form, the drapery close, and the folds few and hard. Yet in many the composition is good, and the action of the figures vigorous. They exactly resemble in style the bronzes still remaining of Etruscan work.
"The mode pursued in painting them was this:
"The intended figure was painted without any previous discoverable outline in varnish, and then resembled exactly those figures so common under the name of Silhouettes. When the varnish was quite dry and hard, the features, the limbs, and the folds of the drapery, &c. were scratched through it with a pointed tool, which was applied with such force as to cut some depth into the clay of the vase. This sort of outlining was sometimes carried round parts of the contour, which appeared to the artist not sufficiently distinct without it. The hands and fingers are often thus partially scratched out. Parts of the drapery and ornaments on the heads of the figures were then covered with a coat of coloured paint. Violet occurs most frequently; often a green, and sometimes white. In some vases of the most ancient and rudest appearances, animals, particularly birds, are coloured not only with these colours, but also red and yellow; and the appearance and style of these vases have a great resemblance to the Egyptian paintings on their mummy chests. The vases of this sort are said to be universally found in the deepest graves, so deep indeed, that over them sepulchral chambers of a later date, with vases of a totally different character are often found. That the colours above-mentioned were put on after the outline was scratched in, is ascertained by the circumstance of the colours having in many instances run into, and partially filled up, the strokes engraved in the vases. This species of painting is evidently the first improvement on the simple Skiagrams.