The lying press was the bookbinder’s main source of apparatus. The rounding is done when the give is in a state of flexibility. The publication must be sufficiently moist to enable the book to be moulded into the round. The book is laid flat on the table with the back away from the operator, the left hand being laid on the sides, and the thumb on the fore-edge. The upper portion is pulled over until the book faces up at a rather sharp angle, the back is then gently tapped with the hammer on the upper portion, and the sections readily yield to the pressure. The book is then turned over and treated similarly on the other side. Several turns of the book are sometimes necessary before the right shape is formed.
The whole of the swelling should not be taken up in the round for it is necessary to reserve some of it for the joints, which equalise the thickness of the boards. The making of the joints is called backing and for this a lying press and pair of backing boards are used.
The lying press consists of two pieces of wood about 3ft in length and 6inch square with a large wooden screw at each end to open and close the two cheeks. In one cheek the screws run free and in the other they run in threads; there are holes in the free sides of the screws in which the iron pin is placed for leverage.
The backing boards are laid each side of the book parallel with the joint at a distance of the thickness of the board subsequently attached. The boards are then lowered into the press until the thickest part of the board is level with the top of the cheeks of the press. The press is then tightly and evenly screwed up first with the hands, and then with the pin. The pressure emphasises the swelling in the book. This is then hammered down each side of the back until a projection has been made which will take the thickness of the boards and remains at right angles with the side of the book.
The theory of a perfectly backed book is that the middle sections are left untouched, but that the sections begin to bend away from the middle in perfect gradation until the first and last sections bend at a sharply accentuated and perfectly creased right-angle, maintaining a good even slope from the crown of the back to both extremes with a good round shoulder to support the boards.