Paper cuts slice completely through the paper fibers so they do not have a
top or bottom feathered edge as you would find in a paper tear. Paper cuts must be repaired with a Japanese repair tissue patch or document repair tape.

Since the cut is unsupported, it might be better to put repair tissue on both sides of the cut or wrap a short amount of the Japanese repair tissue or document repair tape around to the back side of the repair to reinforce the repair.

Follow the instructions outlined in the post for applying Japanese Repair Tissue or using Document Repair Tape.