I've been practicing dots and lines on regular, white printer paper but I'd like to do a real painting for practice. I dont want anything too expensive but it should be sturdier than plain paper. I saw there is "airbrush paper" like the TerraSlate. It looks like I can get 7mm-10mm white. Is this a good paper to use...or any other suggestions? Minimum thickness? Also, I see a lot of tutorials show people using a colored background base (black usually). Did the artist paint the background or can the paper be purchased with different colors. So far I've only seenwhite paper. Thanks for the help!