I had a bag full of sharpies just sitting at my desk and realized I could just throw together a quick holder for them on the glowforge… so I did. Thought I would post incase anyone else would want one. The top holes are about half inch and the holes on the bottom rail are just over quarter inch they are just there so the pens don’t flop around. Hope someone finds this useful. Also it does need to be glued, I really just threw it together quick and didn’t take the time to adjust for kerf. The files is made for 1/8" thick material. I just used medium draft board.