I bolted a linear rail to my 3D printer next to the nozzle and clamped a pen to it, so it applies constant pressure (due to gravity) and there's less risk of destroying the pen/paper. The downside is that lifting the pen is very slow, since it's a lead screw Z axis and there are a couple mm of travel in the rail before the pen carriage hits its stop and actually lifts from the paper.
I agree that the instructions were the tricky part - lots of messing around in Inkscape and Python and manually editing GCode.
I agree that the instructions were the tricky part - lots of messing around in Inkscape and Python and manually editing GCode.