How to easily and cheaply hang artwork?

I have a bunch of paintings I've done from art classes lying around in my room and I havent gotten around to hanging them up. I dont exactly have the money or time to go buy frames and I dont want to really damage my walls with holes in case I want to move around the artwork.

Is there a cheap way to hang them up? If tape is okay, what type wouldnt damage my walls?

Most of my paintings are on flat canvas and artist's paper

Thank you :)