Abstract: A sheet retaining binder is described for detachably holding perforated sheets, the binder comprising a front cover, a rear cover, and a spine, a plurality of sheet retaining rings each ring comprising two portions detachably engaging at one end and hinged at the other; the hinge projecting beyond the sides of the ring and passing through a plate attached solidly to the rear cover such that the hinge axis lies just inside the cover edge and approximately at the middle of the cover thickness dimension. The cover and spine assembly are slotted to allow the rings to pass through. The connections of the covers to the spine and the center-line of the spine are hinged to allow for complete 360 degree rotation of the front cover and any number of contained sheets relative to the rear cover.