Square Bic Pen Holder

thingiverse

This is a compact 20mm tube featuring an 8.15mm aperture running its entire length. Approximately 3mm from the bottom, a 7.5mm diameter hole ensures the pen remains securely in place, preventing it from slipping through. The tube measures 100mm long, roughly 25mm shorter than a typical ink pen, allowing for easy installation of a rubber band to regulate pressure on the writing instrument.