Golite has long claimed to use a special hydrophilic thread that swells when wet and seals the seams on their shelters. I don't know if their thread has real technical merit, or is the product of an ambitious marketing manager, but I do know that I've never sealed the seams on my Golite Hut and Hex and have never had leakage.
So, what is this thread? How come nobody else uses it? And, is it available to the MYOG market?