Many collectors face the dilemma of how to hang or display their prized punchboards to the rest of the world. Punchboards are difficult and expensive to frame, so many simply affix some sort of hanger to the back of their punchboards. While some collectors frown upon this practice, it does make it easier to display your punchboards.
Many punchboard operators added hangers (or worse) to their boards, so the practice seems perfectly logical to me. If you do decide to add hangers to any of your boards, you should probably stick with standard picture-hanging hardware. Try to stay away for the stick-on Tyvek style of hanger pictured here, since they can tear the outer paper covering of your punchboards. Try also to avoid covering up or destroying any of the punchboard's labels or printing.