Got leftover pens, and you also need a spool holder? This is the solution for you! Uses very little plastic and holds your spool well!

Print two of these parts and make sure you have 5 spare or used pens. Then snap the pens into the holes as shown. It's very easy! I used PaperMate Medium 1.2mm Ballpoint pens. Mine came in a pack of 10 for about a buck, but when I went to use them the ink was all dried up rendering the pens useless. Instead of tossing them out I recycled them, which allowed me to make this sweet spool holder.