Here's a similar quick and easy way to do it: Get a 3' peice of spectra, dyneema, or your favorite light single braid. Splice a 3" loop in each end of it. Take your spin sheet, find the middle, pass one loop of the spectra line through the middle of the spin sheet. (I assume you are using a Robline or Mafioli type sheet, which has no cover, so you can easily pass the loop through it.) After you have passed the loop through the middle of the spin. sheet, pass the spin sheet ends through the loop, then run the pigtail back through the loop again, so it won't slip under load. You now have a spin sheet with a spectra tail in the middle, but wait, there's more!

Now, go to your boat, find the clew of your spinn, pass the other loop/end of the spectra tail through the clew, and then pass both spin sheet tails through that loop, so it is now tied to the clew. Run each spin sheet to each side and the spin blocks, and tie them together on the tramp.

So there you go, with only 3 feet of spectra, you can try the pig-tail method on your spin sheets without cutting the sheet, doing any fancy knots or splices, outside of the two 3" loops in the spectra, which is a very easy splice to do.
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