I recently tried sewing a hat out of left over primaloft. I wasn't all that picky about my craftsmanship on this one, so some of the primaloft got sewn with the scrim and some did not. If you are careful about how you sew it, its probably not necessary. Your foot will probably tear into the insulation periodically if you are not careful. Cut it out and practice with the leftovers.
Scott
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I had superhuman powers, but my therapist took them away.