Here's what you'll need to make your very own flag out of vertical blinds.
1 set vertical blinds (the kind you use over a sliding glass door)*
2 cans Dover White Krylon Fusion for Plastic spray paint
2 cans Red Pepper Krylon Fusion for Plastic spray paint
2 cans Patriotic Blue Krylon Fusion for Plastic spray paint
1 roll blue painters tape
1 pair heavy scissors
1 roll double-sided tape
*While you must
use the plastic kind of blinds (vs. fabric), you can pretty much use whatever color you want. That being said, it's much easier to start with a light color so that you'll only need to cover it with a coat or two of paint.
If you don't have a set of vertical blinds hanging around the house, you'll need to hunt them down elsewhere (or buy them, but where's the fun in that?!?). I got mine from Freecycle
. It's amazing what you can get on Freecycle. And sometimes scary.