I first heard about this film about 20 years ago when I was a kid in grade school(!), it just so happened that I was thumbing through the encyclopedias in the classroom one day, and under the entry for movies (or cinema, I don't remember), were several stills for different movies from mainstream to experimental, and one of them shown on the page was a still for OffOn. It really intrigued me, since it stood out the most on the page (it was a still from the film of the scene with the eye with other elements superimposed over it).
About 18 or so years later, the public library here where I live had available for checkout the whole 4-DVD set of "Treasures of American Film Archives" released by the National Film Preservation Foundation. So when I was reading the notes on the DVD cases for the set, I was quite pleasantly surprised to see that OffOn was on one of the discs. After all these years, I could finally see the film! After viewing it, it slightly wasn't was I was expecting it to be (it tended to be a more organic-looking film, not that that's a bad thing, but I was expecting it to have a more electronic aesthetic), but it was still an impressive film, IMHO, considering the techniques Scott Bartlett used to make the film, including hand-tinting the film itself, and using video equipment for some of the film's scenes (filmed off of a video monitor), giving it a more distressed, lo-res look.
Don't get me wrong, the techniques used in this film were quite ground-breaking for 1972. That's why it's still one of my favorite short/experimental films, and a creative inspiration for me as well...