Yep. I have some 18mm neodymium magnets so I made four little pockets for in the back and hot glued them in.

Thank you! Here are the files: https://www.printables.com/model/610016-mickey-mouse-pen-holder

For the past 8 years I have primarily printed things I found online for D&D and whatever was useful without modifying it, except for scaling of course. Anything more intimidated me because that was getting into an artistic realm that is way outside of my comfort zone. But recently I have been doing a lot of retrospective analysis and decided that I am not going to let my comfort zone limit me anymore.