The folks at myDesignLab made long exposure RGB LED drawings using AxiDraw, even going so far as to make multi layer three dimensional drawings.
Lindsay Wilson used a laser in a similar manner, first with long exposure photos, then with a UV laser and phosphorescent vinyl and then with a UV laser and cyanotype paper. The cyano print shown above is an example of his experiments drawing Lorentz attractor patterns.
Our friend Schuyler posted on twitter that he got a laser working with his WaterColorBot. He uses the brush/up down function to move the laser up to defocus when he doesn’t want to engrave/cut.
He even posted sample output: paperboard marked with the word “Laser(s)”. This isn’t the first WaterColorBot laser mod we’ve seen, but it’s the first with demonstrated output!