headchange, i don't think it really takes that much of a bomb proof material for the patch.
i've never seen any sign of problems on the patch it's self. it's the stitching around the edge pulling on the silnylon that shows a problem, putting stress on the silnylon.
but i used the first one (round patch on the ray way) for well over a year w/ no prob.
the round circle probably distributes the force better. but the additional patch on back might help even more.
remember also, i noticed myself at times on this newest tarp pulling & stretching harder than i probably needed to.
i'm still convinced that the additional folded seam on each side will be my next method of attachment. after you sew those circles (especially one on each side of the silnylon) you may decide the same
i need to be sure i choose the right height to run the seam. if i decide for some reason to change the side to side spacing later, i could do so w/ no prob.
shadowmoss, i have some of the griff clips & they work great in certain applications... like securing a corner if the loop pulls out. but they cause a lot of bunching, so i don't think they would be great for this use. but if you decide to give them a try, let us know one way or the other<g>.