Blankman (1994) on Netflix

Darryl Walker is a nerdy, child-like man with a genius for inventing various gadgets out of junk. After tragedy hits his family, and when he stumbles on a method to make his clothes bulletproof, he decides to use his skills to become the lowest budgeted superhero ever. His brother Kevin disapproves of Darryl fighting crime as "Blankman", but soon finds himself fighting alongside his brother as "Other Guy", an easily overlooked partner with no special weapons or crime-fighting abilities.