Verb
paint with a broad brush (third-person singular simple present paints with a broad brush, present participle painting with a broad brush, simple past and past participle painted with a broad brush)
(idiomatic) To describe a class of objects or a kind of phenomenon in general terms, without specific details and without attention to individual variations.
It's obviously unfair to paint with a broad brush here, but the germ of an idea for a breakthrough in technology doesn't come out of a business school curriculum. It comes out of a laboratory or a math lecture or a physics tutorial. Michael Moritz