airnut57,

I think you may have been led to believe the hardware store blue low tack tape is what people are using to paint their models. Really, its only another variety of plain masking tape.

You're looking for the blue 3M Fine Line Tape brand that is generally only carried by automotive paint shops and maybe at the occasional LHS. It comes in multiple widths and is around $6-7 a roll. Mostly I use 1/4" or else 1/8" for sharp curves. There are wider widths. You have to burnish the tape down with your fingernail to make it run proof, particularly at the tape intersections. You can tell if you got it right because the tape turns a darker color when it's burnished down. if you're worried about pulling up the paint when you take the tape off, pull it back over itself after warming it up with your monokote heat gun.

There are other brands that come in green and red. I've used both but the blue fine line tape is the right stuff for paint masking. You can use the blue low stick stuff to hold the paper masking.