I used to paint Scoots (helmets, tanks, fenders, leather jackets, you name it I painted it.) back in the day. I used a pasche VL and most often the Createx paints for just about all of my artwork. Unless I needed some special stuff I used custom eurethane paints, basecoats and such. When I masked stuff off on custom painted parts, I would first lay down the base coat the way I wanted it. Then a few thin coats of clear. this would protect my basecoat. I would let it cure and bump the gloss off of it with some emery cloth or wet sander. I'm talking very fine grit, 600 ( if that serves me right, it's been a while). Using a degreaser thats safe for urethane I prep the surface for the masking. I used High Quality 3M masking tape( no cheap brand) for the bulk areas, and pinstripe tape for getting in close. I would lay the masking tape over the instripe and using an exacto , cut the masking ON the stripe, this keeps you from cutting into the paint underneath. I hope this helps. Thjis is old school though, I'm sure there are better ways these days, but I used to get super results with this method. The key is don't settle for cheap ass materials. You get what you pay for. And where some laytex gloves to keep your finger grease off of the surface.
You might want to buy some scrap metal (non rusty) and do some practice runs. I did this for a long time before practicing on some bro's scoot (not a good idea).
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