Like most kids, the boys can go through a ton of paper with all the art & doodling they do on a regular basis. So in an effort to save a little paper (and cash!) we’ve started drawing on all sorts of cardboard from stuff that we already bought, like turning cereal boxes inside out and drawing on them, cracker boxes, anything that you’re going to throw away anyways and that can be drawn on works! You can also use the boxes to make ramps for cars or use as houses for games.
Of course it’s nice to just use regular paper too since you can actually save their artwork long term that way, but cardboard is a nice extra that’s free when they’ve already used a good amount of paper. Oh, and you can hang up their art on a nail and it looks like a cute painting.