Figure A1
The image contains four separate photos of old books with different types of leather bindings. The top left photo shows a book cover with the word 'Diario' written on it. The top right photo shows the spine of a book with leather binding. The bottom left photo shows a book with leather on the corners of the cover and on the spine. The bottom right photo shows a book with a cardboard cover and a leather spine.Examples of binding from various books