Any coloured or newly printed plates will need tissues, as in the former pressing; and any folded plates or diagrams or inserted letters will need a thin tin on each side of them to prevent them from marking the book.
Again, the pressure on hand-printed books must not be excessive.
The books should be left in the press at least a night. When taken out they will be ready for headbanding, unless the edges are to be cut in boards.
CHAPTER X
Cutting in Boards—Gilding and Colouring Edges
CUTTING IN BOARDS
The knife for cutting edges may be ground more acutely than for cutting boards, and should be very sharp, or the paper may be torn. The plough knife should never be ground on the under side, as if the under side is not quite flat, it will tend to run up instead of cutting straight across. Before beginning to cut edges, the position of the knife should be tested carefully by screwing the plough up, with the press a little open, and noting whereabouts on the left-hand cheek the point of the knife comes. In a press that is true the knife should just clear the edge of the press. If there is too much packing the knife will cut below the edge of the press, and if too little, it will cut above.
“Packing” is paper inserted between the knife and the metal plate on the plough, to correct the position of the knife. When by experiment the exact thickness of paper necessary for any given knife is found, the packing should be carefully kept when the knife is taken out for grinding, and put back with it into the plough.
The first edge to be cut is the top, and the first thing to do is to place the boards in the position they will hold when the book is bound. The front board is then dropped the depth of the square required, care being taken that the back edge of the board remains evenly in the joint. A piece of cardboard, or two or three thicknesses of paper, are then slipped in between the end paper and the back board to prevent the latter from being cut by the knife. The book is then carefully lowered into the press, with the back towards the workman, until the top edge of the front board is exactly even with the right-hand cheek, and the press screwed up evenly. The back board should show the depth of the square above the left-hand cheek. It is very important that the edge of the back board should be exactly parallel with the press, and if at first it is not so, the book must be twisted until it is right.
The edges can now be cut with the plough as in cutting mill-boards. The tail of the book is cut in the same way, still keeping the back of the book towards the workman, but cutting from the back board.