I spray onto newsprint, paper, canvas, wood, leather, anything. The ones that are in my gallery like the Hijabis are on canvas, the rest on paper. If you use wood, make sure you seal it with gesso or you paint layers on top of it. I go to Home Depot and buy the oops paint. They're a dollar and it's house paint so your wood will seal and you can spray it white and thats' it, you have a wood panel.
I'm going to post more tutorials this and next week. I'll be sure to put a wood panel one on there.