Please do not mistake me. I am saying my true opinion from my experience. I was an avid viewer of the so-called 'art films' during my college days. Post college and teens, and on a review, I now feel that at least those days art films are movies that are shot in almost darkness, the time gap between two dialogues is half an hour and you end up with breaking your head what is the actual story and theme.
I had seen a lot of art films in Bengali, Malayalam , Kannada and Marathi during 70 s and eighties. One or two in other languages also. But I just do not recall most of them now. If I would watch any of them now, I cannot stay awake for more than two minutes.
Commenting on an art film in those days, one critic wrote" What is there in the film........(name of the movie) apart from the hairy armpits of the hero and the wide open eyes of the heroine as shown throughout the film."(I do not remember verbatim, but this is the essence of the matter).
Most of the art films were shot with low expenses and they survived mainly on the subsidy and tax concession given by the government. Some were made only for sending to awards and predictably they got awards. But probably not more than a few hundred people saw the film.