Am lucky enough to have my own vinyl cutter, will only cut 6 inch tall letters max but works well. Went through all the sign vinyl and frisket I could stand then finally settled on white Contact shelf paper. Frisket was too sticky, so tried low tack frisket, worked OK but being clear it was difficult for these old eyes to see the stuff when I was trying to position small graphics. Sigh vinyl works OK and isn't clear but like frisket it's a whole lot more expensive than shelf paper.
I haven't found a down side to shelf paper, it's inexpensive, haven't had any trouble with paint bleeding under the edges and it is easy to remove. I use hardware store low tack masking tape for a backing to hold everything in place when applying the stencil to the airplane making for a cheap system that works. All the Graphics on the two SHIMS pictured in the Brodak .25 thread below were done with shelf paper.