A binder system is disclosed that flexibly secures one or more flat objects including by mechanical grasping of flat-shaped or sheet materials in a central spring clamp having a compact cross-sectional geometry that can adapt to several sizes of clamped materials and uses. The spring clamp comprises an elongated tri-folded spine with a flat central portion and flat side portions, and flat cover supports that are attached by hinged means to the side portions of the spine. The flat central portion aids a user in opening and keeping the system in its open configuration. In some aspects the system includes customizable covers attachable to said cover supports.