It is here of the utmost importance that the greatest attention should be given to careful paring of the leather, especially seeing that the leather is not too thick in the joint; if so, it must be reduced to the required thickness. It must be pared at the head so that the turn-over does not appear any thicker than the rest of the back. Leather used for covering books must be worked with paste, and paste only.
Figs. 69 and 70—The head: good and bad.
It must be drawn tight over the bands, and these should be well rubbed down with the folder. The turning-in is done in the same way, but the overlap—as far as the actual width of the book is concerned—is again drawn out so that it projects about 2 mm. over the headband.
This projecting leather is pressed quite flat—not slant-wise—over the headband, so that seen from above it almost covers the latter.
All half and full leather bound books have the corners of the boards next to the head pared down. This is done before covering—it not only makes the turning-in easier but the book has a better appearance and opens better.
When the turning-in is finished, the book is opened wide and the boards adjusted so that both turnings-in are uniform and sharp and also that it has already, to a certain extent, a deep groove, and then closed. If no layer of waste paper has previously been sewn in, it may now be placed in the joint, so that after drying the boards may open quite freely and nicely.
The closed book is now "tied up," that is to say, a cord is looped and tied right round the back at the joint. The turn-in is thus drawn in at the pared-down parts. Behind the cord the head and tail are pressed down with the folder to right and left, slightly outwards; whatever may have been drawn in by the cord is put right on the inside edge and the edges are rubbed sharp and square with the folder. The book is lying throughout on the paring stone, not upon the press-board.
The foregoing applies to made cases as well as to those backs which are pasted on the books. With the former it is necessary to round the backs. This is done by drawing the back underneath a folder with a wave-like motion. It can easily be done after being once seen. To give the back a good hold on the book from the very outset, the inserted part is pasted narrowly at the joint before being laid on the pasted leather so that at this place it firmly adheres to the back.
Backs that are stuck to the book itself are cut open about 2 cm. long at the joints with a small knife in order to take the "turn-in"; for the rest the work is the same.