The workmanship of Hendrik Goltzius, for instance, and still more that of his pupil, Jan Müller, is strained and feeble owing to their affectation of ease. The constant use of bent and parallel lines unreasonably prolonged imparts to the plates of these two engravers an appearance at once dull and florid; they present something of the same aspect as those caligraphical specimens of the present day, in which the faces of Henri IV. or of Napoleon are drawn entirely with the curves of a single stroke. Still, in spite of this extremely affected workmanship, the prints of Goltzius, of Müller, and even of Saenredam, are characterised by a comparative intensity of tone, as well as by singular skill in cutting the copper. This abuse of method, however, had not yet become general in the schools of the Low Countries. Side by side with the intemperate or daring craftsmen we have mentioned, there were certain Flemish and Dutch engravers who imparted to their work a delicacy and a reticence of expression better suited to the traditions and the models bequeathed by Lucas van Leyden. These were Nicolas van Bruyn at Antwerp, the brothers Wierix at Amsterdam, and some few others, all of them disciples more or less faithful to the old teaching, and apparently more or less hostile to the effort at emancipation going on around them. When, however, Rubens took the reins, individual resistance and impulse ceased, and all controversy was at an end. Principles, method, and aim became the same for every one. Both Dutch and Flemish engravers openly set themselves to represent with the graver the infinite gradations of a painted canvas, the delicacy and the daring, the nicest punctilio and the most summary smearing, of the painter's brush. Never was the influence of a painter on engraving so direct or so potent as that of Rubens. The great master had shown by his drawings that it was possible to be as rich a colourist with black and white alone as with all the resources of the palette. He made choice amongst his pupils of those whom he believed to be capable of following his example in this matter; he obliged them to lay aside the brush, almost ordered them to become engravers, and so penetrated them with the secret of his method, that he seems to have animated them with his own inspiration. He assembled them in the vast house which he had built at Antwerp, and which he turned into a college of artists of all sorts. He made them sometimes labour beneath his eye; he carefully corrected their work;[28] and in this way he taught them that comprehension of effect which was specially his, and his own incomparable knowledge of the right tones with which to lay in, or to support, a mass of light or shadow.