One of my most common art processes involves xeroxing. As far as I know, I "made this up", though it's no secret, and I'm sure other mixed media people have experienced this effect.
First I make lots of graphite and gouache drawings. Then I make copies of them...I play with the size of things, making smaller and larger versions.
Pictured here is the next step, when I collage parts of the copies together into new compositions. I can keep things I like about the original drawings, and change things I don't like.
Once I make a collage I am into, I xerox that onto any paper I want. Often I choose black paper. I have to buy this at art stores because copy places never have black paper. When I have the black on black xeroxed drawing, I can paint onto it with gouache. The xerox toner repels the gouache to a certain extent. The result is clean, beautiful, and matte, resembling silkscreen.