Lack of means may make it easy for a bookman to resist the temptation to supplement the illustrations in a book with duplicates in proof or any like extravagances, but even then few books which have plates in them fail to bring trouble. If the plates are protected with "flimsies," the owner's conscience may be perturbed with doubts as to whether these may lawfully be torn out. If there are no flimsies, the leaf opposite a plate often shows a set-off from it and is sometimes specially badly foxed. Moreover, not being an integral part of the book, the plate presents problems to publishers and binders which are too often left unsolved. It ought to be printed on paper sufficiently wide to allow of a flap or turn-over, so that the leaf can be placed in the quire and properly sewn. But the flap thus left is not pretty, and unless very thin may cause the book to gape. Thus too often the plate is only glued or pasted into its place, with the result that it easily comes loose. Hence misplacements, imperfections, and consequent woe. It is the charm of the earlier books illustrated with incised engravings that the impressions are pulled on the same paper as the rest of the book, very often on pages bearing letterpress, and almost always, even when they chance to occupy a whole page, the back of which is left blank, as part of the quire or gathering. The price, however, which had to be paid for these advantages was a heavy one, the trouble not merely of double printing, as in the case of a sheet printed in red and black, but of double printing in two different kinds, one being from a raised surface, the other from an incised. It is clear that this trouble was found very serious, as both at Rome and Florence in Italy, at Bruges in the Low Countries, at Wurzburg and Eichstatt in Germany, and at Lyon in France, the experiment was tried independently and in every case abandoned after one or two books had been thus ornamented. [Illustration: XXXIV. FLORENCE, NICOLUS LAURENTII, 1477 BETTINI. MONTE SANTO DI DIO. CHRIST IN GLORY. (REDUCED)]