Since 1969, Minneapolis-based Roman Verotsko has utilized electronics and programming to create beautiful algorithmic plotter drawings.
Presently, many artists are utilizing CNC machines to create vector, geometric, organic and multiples of drawings on all scales. They are using sharpies, felt tip pens, ball point pens, pencils, etc.
Cambridge, Massachusetts-based engineer Aaron Panone has collaborated with graphic designer Matt W. Moore to create a series of geometric sharpie drawings, some seen below.
Paul Ferragut's Time Print Machine creates images in the usual CNC manner, with dots forming a halftone pattern as the arm moves across the page. What is different about this device, is the incorporation of a special program which takes the grey value of a pixel and converts it using a time-based algorithm.
...the felt pen remains in contact with the blotting paper for relative periods of time. Consequently the ink will bleed through the paper creating a variety of different sized stains, gradually building the image.