I painted my Triumph (so: just one bike), but I used an HVLP gun not rattle cans. After I posted I realized it probably would be easier to just lay your 1/8" tape, paint the rest, then remove the tape and mask the edges. I like Bruce's suggestion but for my next paint job I bought some special pin striping masking tape. It comes in different widths, mine is also 1/8". You lay the whole thing down and remove the central part where you want the pin stripe. You still need to mask everything else around it, though, if you are spraying. I haven't yet decided if I will spray the stripes with an air brush or just use a hand brush. A hand brush wouldn't require extra masking, but I want to play with my air brush and I'm sure it will give a flatter surface.