This is just a curiosity thing...but what's the most random surface you've drawn on. What did you draw? Do you have a picture of it? :]
I think mine are probably randomly drawing Ke$ha on a balloon in my science class, or drawing a kid about to get hit by something falling from the sky on a lab table lol (stayed there all semester though :]) I've had to draw on people before, that one was a little weird due to the scale of the drawing...no pics of that though :]
(neither of them are very good but they were both literally only 5 minutes tops lol)
Balloon:

Table:
I think mine are probably randomly drawing Ke$ha on a balloon in my science class, or drawing a kid about to get hit by something falling from the sky on a lab table lol (stayed there all semester though :]) I've had to draw on people before, that one was a little weird due to the scale of the drawing...no pics of that though :]
(neither of them are very good but they were both literally only 5 minutes tops lol)
Balloon:

Table:
