I just watched this documentary. The entire concept of art brut/outsider art is fascinating. and Henry Darger was definitely a fascinating, mysterious, kind of creepy (and yet kind of sweet and innocent-seeming) man--with a very distinctive style of painting/drawing/collaging/tracing.
And what prolificness! pages upon pages upon pages! and no one knew.
I actually like it quite a bit. The colors and composition are so bright and inventive and fantastical.