They make removable spray paint also, it comes off really easy.
I've never been I much for patterns, per say, I've spray painted alot of guns and usually just do a base coat and then break it up with a couple other colors. I did a friends shotgun and he told me it was to effective. He had leaned it against a tree to light a cig and then stepped away to answer a call of nature. He said it took him a minute to find his gun.
The nice thing about patternless blotchy paint jobs is durability doesn't really matter, if the paint gets to worn just reapply some over top. They may not look as cool but they are effective, and you can modify them for the seasons.
The nice thing about duracoat is it helps protect the gun from the elements better than paint ever dreamed of. And you need an airbrush to apply it.
I prefer the Krylon flat finish camo paint sold at wal-mart, the one with the comoed jeep on the front of the can.