Also you will want to paint from dark to light. For masking you can use liquid mask, blue painters tape, or even lessens favorite, clear plasti-dip spray. (I still need to try this one). Whichever method you choose make sure you spray light even coats with a lexan specific paint, i.e. Pactra Acryl (my favorite), it's water based so clean up is a breeze, and pretty much odorless, pactra rattle cans, tamiya rattle cans for lexan, and if you have to you can use parma paint (I personally hate the stuff!) You can also use Createx paint sold in the airbrush section of Michaels arts and crafts, but thats just basically rebottled parma faskolor.