An alternative approach to the Camo pattern is to use Jamb Tape. Its a round foam tape sold at autobody shops. It's for putting on car door jambs to keep the paint off of them.
Its has a sticky side that you can just put down on your Camo Pattern and then shoot paint against it. Works very well and there's no over spray.
The RAF Depots used Masks on the wings and and fuse to get the outlines for the Camo. Just an FYI.