As to the artistic quality of the designs which are found in these books, they are of very various quality, those of the earlier sixteenth century with woodcuts being naturally the best and most vigorous, corresponding in character to the qualities of the contemporary design. Holbein's "Dance of Death," or rather "Images and Storied Aspects of Death," its true title, might be called an emblem book, but very few can approach it in artistic quality. Some of the devices in early editions of the emblem books of Giovio, Witney, and even the much later Quarles have a certain quaintness; but though such books necessarily depended on their illustrations, the moral and philosophic, or epigrammatic burden proved in the end more than the design could carry, when the impulse which characterized the early Renaissance had declined, and design, as applied to books, became smothered with classical affectation and pomposity, and the clear and vigorous woodcut was supplanted by the doubtful advantage of the copper-plate. The introduction of the use of the copper-plate marks a new era in book illustration, but as regards their decoration, one of distinct decline. While the surface-printed block, whether woodcut or metal engraving (by which method many of the early book illustrations were rendered) accorded well with the conditions of the letter-press printing, as they were set up with the type and printed by the same pressure in the same press. With copper-plate quite other conditions came in, as the paper has to be pressed into the etched or engraved lines of the plate, instead of being impressed by the lines in relief of the wood or the metal. Thus, with the use of copper-plate illustrations in printed books, that mechanical relation which exists between a surface-printed block and the letter-press was at once broken, as a different method of printing had to be used. The apparent, but often specious, refinement of the copper-plate did not necessarily mean extra power or refinement of draughtsmanship or design, but merely thinner lines, and these were often attained at the cost of richness and vigour, as well as decorative effect. [Illustration: GERMAN SCHOOL. XVITH CENTURY. REFORMATION DER BA[:Y]RISCHEN LANDRECHT. (MUNICH, 1518.)] The first book illustrated with copper-plate engravings, however, bears an early date--1477. ["El Monte Sancto di Dio." Niccolo di Lorenzo, Florence]. In this case it was reserved for the full page pictures. The method does not seem to have commended itself much to the book designers, and did not come into general use until the end of the sixteenth century, with the decline of design.