frotton, or by friction, or by rubbing in some form or other. One writer of rare simplicity has hazarded the opinion that the back of the paper, or the frotton, may have been soaped to facilitate the work. But these methods of printing books are imaginary and entirely impracticable. The shining appearance on the back of the paper does not prove that the prints were made by friction. The gloss could have been produced by any press which gave a hard impression against a harder surface. It could have been produced by rubbing or smoothing down with a burnisher the indentations of the lines on the back of the paper, as is sometimes done by pressmen of this day when they take too hard an impression. Some copies of the book show the results of hard impression. Two of the four copies of the Bible of the Poor in the possession of the British Museum present lines deeply sunk in the paper, as if they had been printed from a press. Jackson, a practical engraver on wood, who had large experience in proving wood-cuts, has unwillingly accepted the unauthorized tradition of presswork by friction, but he has candidly stated its difficulties.
"Considering the thickness of the paper on which the block-books are printed — if I may apply this term to them — and the thin-bodied ink which has been used, I am at a loss to conceive how the early wood engravers have contrived to take off their impressions so correctly; for in all the block-books which I have seen, where friction has evidently been the means employed to obtain the impression, I have noticed only two subjects in which the lines appear double in consequence of the shifting of the paper. From the want of body in the ink, which appears in the Apocalypse to have been little more than water color, it is not likely that the paper could be used in a damp state, otherwise the ink would run or spread; and even if this did not exist, the paper in a damp state could not have borne the excessive rubbing which it appears to have received in order to obtain the impression. Even with such printer's ink as is used in the present day — which, being tenacious, renders the paper in taking an impression by means of friction, much less liable to slip or shift — it would be difficult to obtain clear impressions on thick paper from blocks the size of those which form each page of the Apocalypse, or the History of the Virgin. ... A block containing only two pages [of the History of the Virgin, a block of smaller size than that used for the Bible of the
