Abstract: A bookbinding repair kit containing instructions, diagrams and equipment to carry out repair to damaged or torn backing shoulder joints of any book, the equipment comprising a complete endpaper consisting of one evenly folded sheet of paper with a double-sided adhesive strip no less than 7 mm and no more than 10 mm in width but of a particular length, with a peel away backing paper attached to the endpaper adjacent one side of the endpaper fold, a double-sided self adhesive strip of mull cloth of a particular width and length, two thirds of each side of the mull cloth being covered with a peel away backing strip and the remaining third adhered to the adhesive side of a sconelined, one sided self-adhesive paper the same size as the endpaper, the endpaper side without the adhesive strip being glued to the plain side of the scorelined paper.