I first came across the metal binder idea from Instructables. I then came across the traffic sign binder via Make. Having a middle schooler who can’t seem to keep a binder intact for longer than a week the metal binder idea appealed to me.
At first I was going to use sheet metal but came across an old STOP sign at a construction recycling center. The rest of the materials consist of a piano (continuous) hinge, a donor binder, and some rivets.