626,366. Binding edges. HUY, F. P. d'. Dec. 24, 1946, No. 37807. Convention date, Oct. 26, 1943. [Class 42 (i)] [Also in Group XV] In a book binding case of the type in which the covers consist of cardboard or similar material, having folded over edges, the doubled edges are provided with a groove or similar indentation parallel to the edge portion which possesses a substantial flexibility in the longitudinal direction with freedom from cracking at the edges. The groove 5 or similar indentation may be provided on the inside or the outside face of the cover, or on both the inside and the outside.