quarter subsidiary cores (Q1168)

Subsidiary cores placed along the upper front and/or back of the main core, corresponding to NE or NW on a compass dial when looked at it in cross-section. They may be placed either on the front or back of the endband core, but are usually found used together in combination with a back-bead core. They were often used on late medieval bindings, worked with secondary sewing through the primary covering material.