Abstract: A binder spine with a generally rectangular back panel that has a width and a length. The back panel is bounded by generally opposed longitudinal edges. The opposed longitudinal edges are joined through living hinges to adjacent side panels. The binder spine is foldable along the living hinges between an open generally flat configuration and a generally closed configuration. At least one post member is located on one of the side panels, and at least one socket member is located on the other side panel. The socket and post members are aligned with one another and include generally cylindrical mating walls. The post and socket members are spaced apart in the open configuration by a distance. The socket and post members are positioned to retainingly interengage one another in the closed configuration to hold the binder spine in that closed configuration. The socket in the socket member receives the post member in a snap fit.

Abstract: A binder spine with a generally rectangular back panel that has a width and a length. The back panel is bounded by generally opposed longitudinal edges. The opposed longitudinal edges are joined through living hinges to adjacent side panels. The binder spine is foldable along the living hinges between an open generally flat configuration and a generally closed configuration. At least one post member is located on one of the side panels, and at least one socket member is located on the other side panel. The socket and post members are aligned with one another and include generally cylindrical mating walls. The post and socket members are spaced apart in the open configuration by a distance. The socket and post members are positioned to retainingly interengage one another in the closed configuration to hold the binder spine in that closed configuration. The socket in the socket member receives the post member in a snap fit.