I have built one Skin on Frame with 3.7 oz dacron and one with 10 oz polyester. The dacron, finished with the Stitz aircraft process, is very, very vunerable to puncture. The polyester is finished with spar varnish is far more durable. There are other ways to finish such as Epoxy that will maintain taughtness better than varnish. Mark Starr at Mystic Seaport uses 10 oz nylon, shrunk with water and painted with great success for first time builders. I have holed the 10 oz nylon and the 3.7 ox dacron. I thought I structurally broke the boat when I holed the nylon, I have no clue how I holed the dacron.

Pete Strand