I used the idea of the dovetail rails and designed a low profile holder that does not impede normal printing. I use this in conjunction with a python script I wrote as a school project that turns SVG files into GCODE but you can just whatever software you want.

After installation, add a rubber band around the slide and hook it around the bottom of the bracket. This pushes the pen down and ensures proper contact with the paper. The dovetail provides necessary stability againsty vibration and lateral forces. Pen is held in place with two thumbscrews.