Album or book with pages formed by concertina folding elongate sheet

摘要

The pages are formed by concertina folding elongate sheet 10 (Fig 2) along fold lines 12,13 which define alternate wide and narrow portions A,B. The wide portions A include upper and lower trapezoidal flaps 16,17 defined by folding lines 14,15 which are folded inwardly and attached to the wide portions (Fig 3). Concertina folding of the elongate sheet results in a double-layer page construction (Fig 4). Trapezoidal indentations 19 of the outermost pages receive trapezoidal flaps 21 of a pair of hard covers 20.