The instruments which were employed for the painting of the vases were not, as formerly supposed, limited to a metal or reed pen, and a camel’s-hair brush. It has been recently pointed out in a most illuminating article by Dr. Hartwig[800] that the lines of black bordering the figures on red-figured vases are usually double, the space in between being filled in with varnish thus: [ornament]. Practical experiments have shown that this can be obtained with a _feather brush_ or pen, drawing the lines separately, not concurrently, as might be done with a metal pen.[801] The feathers of the snipe were specially suitable for this purpose, as were also those of the swallow. It is probable that we see the use of the ordinary brush on the Ruvo vase-painting already mentioned, but this was no doubt used for filling in the ground and all parts where the colour was laid on in large masses. Again, on a fragment from the Athenian Acropolis (Fig. 73)[802] a man is seen covering the inside of a B.F. kylix with black varnish while he turns it on the wheel; this is also done with an ordinary brush. But there is a R.F. kylix,[803] on the interior of which we see the undoubted use of the feather-brush or pen (Fig. 74). In his left hand the painter seems to hold the sharp tool for engraving the outlines of the figures, and with his right he manipulates the feather-pen which is seen to consist of a small feather inserted in a wooden holder. [Illustration: FIG. 74. VASE-PAINTER USING FEATHER-BRUSH.] It is not likely that this instrument was generally used before the introduction of the R.F. style; it would hardly have been required either for the silhouette figures of the B.F. vases or the outlines on the white ground. According to Hartwig, Andokides, one of the earliest R.F. artists (about 520 B.C.) was making experiments in the use of the feather-pen, and in the course of twenty years, in the vases of Epiktetos and his school, its use had become general. It is not indeed unknown on B.F. vases, and can be traced in the ornamentation where fine lines were required, as on the Amasis vase in the Bibliothèque Nationale.[804] It was probably first used in the more developed Ionic pottery, but as we have seen had no chance of becoming generally used until the essentially linear R.F. style came into vogue. The artists who reached the height of skill in its use were Meidias and the painters of the delicate little vases of the latter half of the fifth century, this instrument being also admirably adapted for making the fine inner lines in which the painters of that period achieved such success.