How is your luck with pin striping? Well with so-so results, I called Dennis Desprois to find out what he uses. It is called Prostripe, it is a high performance automotive striping.
The use of pin striping is to provide a water tight seal for a boat's mylar decking. Without it, water can and will find leak points into the hull. With water leaking in, your boat obtains more weight and your electronics can be damage.
With this in mind, it is a good idea to use striping that works. The first step is buy the 5/16" wide striping. This will give plenty of striping to work with. Next, thoroughly clean both the top edge of the hull and the top edge of the deck. Then when appling the striping, don't stretch it, just use care if you have to reposition it. Once on, smooth with a cloth and let be for 24 hours before any sailing.
One nice side effect to pin striping is it makes your boat look great! Isn't that what it is all about, besides winning, of course!