[Illustration: PROVER. XXI. FIG. 51.--LÜTZELBURGER. The Rich Sinner. After Holbein.] Little by little, however, the domain of wood engraving widened, or rather the object which wood engravers set themselves to attain was changed. Instead of confining themselves, as in the past, to the part of commentators of authors and illustrators of books, they set to work, like the line engravers, to publish, in larger dimensions than the size of a book, prints reproducing separate drawings and sometimes even pictures. The works of Titian specially served as models to skilful wood engravers, some of whom, Domenico delle Greche and Nicolò Boldrini amongst others, are said to have worked in the studio, even under the master's own eye. According to the careful testimony of Ridolphi, confirmed by Mariette, Titian gave more than mere advice. He seems, more than once, to have sketched with his own hand on the wood the designs to be reproduced by the wood engravers; and amongst the prints thus begun by him, several "Virgins" in landscapes and a "Triumph of Christ" may be mentioned: the last "a work," says Mariette, "drawn with fine taste, in which the hatchings forming the outlines and shadows ... produce a softness and mellowness understood by Titian alone." However brief the preceding observations on the progress of engraving in the sixteenth century in Germany and Italy may appear, they will perhaps be sufficient to indicate the reciprocal influence then exercised by the engravers of both countries. Without ceasing to be Italian in their real preferences, their tastes, and their innate love of majesty of style, Marc Antonio and his disciples understood how to improve their practical execution by Albert Dürer's example, exactly as Dürer's pupils and their followers, while continuing to be German as it were in spite of themselves, tried to become Italianised as best they might. But it is time to speak of the school of the Low Countries, which appeared to stand aloof, as much from the progress in Germany initiated by Martin Schongauer and Albert Dürer, as from the more recent advance in Italy. Apparently unaffected by external influences, it was content to rely on its own powers, and to make use of its own resources, whilst awaiting the time, now close at hand, when it should in its turn supply example and teaching to those who had till then believed themselves to be the teachers. CHAPTER V. LINE ENGRAVING AND ETCHING IN THE LOW COUNTRIES, TO THE SECOND HALF OF THE SEVENTEENTH CENTURY.