The Solution!
Perform the following at your own risk!
I had extra tape, so I decided this would work well as a textured grip for the magazine. The challenge was cutting the tape into these pieces for each of the squares on the PMAG.
Art supplies to the rescue! Sort of.
Using tracing paper, I traced each unique shape of the PMAG. I cut the tracing paper shape and traced that onto a piece of stiff cardboard. Then, I used the cardboard shape as a template to cut the textured tape.
It's essential to clean the space where the tape will go with rubbing alcohol or a suitable cleaner. Once I had every shape and quantity cut, I applied the cut pieces to the spaces in the PMAG. The adhesive backing on the tape is very strong.