A quick view of how well a 0.8mm tip Sharpie pen works on a 3D printer retrofited with a pen holding bracket. The pen bracket can be used with several different pens and can be adjusted by heating the plastic clip with a lighter. It's great for drawing on a blank PCB for etching your own circuit boards or on most paper materials.
Next time I will draw onto a PCB with a photoresist because the marker came off the copper very quickly in etchant solution. I would also use a 0.1mm pen from an Arts and Crafts store.
This is on a MakerGear M2 3D printer. You can print this bracket from: https://www.thingiverse.com/thing:2372298
