After the corner book board is repaired, cut a piece of new book cloth to cover the repair. The grain of the book cloth (see separate post) must run parallel with the spine of the book.
Glue the book cloth patch in place on the outside of the book cover. Dry under weight.
Fold the point of the new book cloth corner over the book board so it forms a 45 degree angle. Use a needle-in-a-stick to mark the position where the book cloth covers the corner. This mark should be as close to the edge of the corner as possible
Unfold the new book cloth corner and draw a line through the needle point, along the 45 degree fold. Cut the book cloth along this line.
The new book cloth patch has two edges. Regardless of which corner is being repaired, in these instructions the top or bottom edge of the book will be designated as the top. The other edge will be the fore edge of new book cloth patch.
Apply PVA along the top edge of the new book cloth then fold the edge over the book board. Use a folder to press the book cloth flush against the thickness of the book board. The book cloth should be glued completely flat to all sides of the book board.
The new book cloth has a tendency to bulge out at the corner so push the new book cloth downward against the front edge of the book board with the point of a folder.
Apply glue to the fore edge of the new book cloth and work the cloth into position over the book board with a folder. Use a folder to work the new book cloth flat against the book board and slightly round the corner.
The original cloth can be trimmed to eliminate the ragged edges and glued down or the ragged edge can be glued as is. Gluing the loose threads down can sometimes help camouflage the new book cloth if it is not a good color match.
Dry the repair under weight using paper covered bricks or between
pieces of book board with bulldog clips. Some older books may look more “natural” with rounded corners, especially if only one comer is being repaired. For rounded comers, mold the corners into position while the glue is wet; dry without weight or pressure.