Binder construction for easy insertion and removal of spine label

In a binder such as a window binder having two opaque thermoplastic sheets sandwiching therebetween front and rear panels and a spine panel and an outer clear thermoplastic panel forming a window over at least the spine, the outer surface of the spine panel has a depression formed in it such that the spine is thicker or otherwise raised near its vertical edges, and thinner or otherwise depressed between the raised portions. The opaque sheet covering the outward face of the spine panel is sufficiently flexible so as to deflect inwardly into the depression in the spine panel. The deflection of the thermoplastic sheet into the spine depression allows a spine label to be inserted into the pocket between the thermoplastic sheet with relatively little force.