After recently skinning my SOF frame, I thought it might be a good idea to see how the material absorbs the polyurethane, and how the poly looks when tinted with artist oil paint. I did this to reduce the chances of any 'surprises' when I actually go to shrink and seal the skin. I was amazed at how easily the nylon scraps absorbed the tinted poly - it soaked right through and onto the newspaper I had put down. Much easier to saturate than the 10 oz cnavas and latex paint I recently used for my daughter's kayak. And even with just a tiny amount of oil paint,the nylon and poly really held the colour.
Most surprising was the 'strength' or 'abrasion' durability test we did. After the scraps had dried/cured for a couple days, I had my children take a screwdriver and try to puncture the nylon. We tested both uncoated and the coated scraps. My children are only 8 and 11, and neither one is a brute when it comes to strength, but both were able to easily puncture the uncoated nylon. The coated nylon, with only one coat of tinted poly was actually VERY tough to puncture! I know, 'cuz I tried, too !
I know that a much more scientific experiment was done some time ago , I just thought that I would add this anecdotal comment. Perhaps it will help someone who might be thinking about covering a frame, and is undecided between nylon and canvas!!