I'd had this idea for a while and finally got around to designing and printing it. A simple, low poly pen holder. The hole diameter has been increased to fit up to a 12mm pen. If a larger diameter is needed the you will need to scale as needed. 3D printing settings layer height: 0.16mm supports: yes, i recommend tree supports from cura, buildplate only infill: 25 - 35% i also recommend a brim to further support the bases of the tree supports.