uh guys...those look just like the peel and stick canoe tie outs i have seen in canoeing catalogues...it is already sewn and all you do is peel it off the backing and stick it to the canoe where ever you want a additional tie out....all you would need to do is stick it where ya want ..then add a little light sewing..problem solved...as i recall ...i think they run like 4 bucks for 2..try campmore or one of the canoe/khyak places.....
juts my 2 cents worth
that wouldn't add any strength, it's reinforced, because the pull tab is stitched to the patch (instead of the lightweight fabric), and the patch is plenty strong as a single layer, now the weak link in the chain is the larger circular area of stitching, the force spreads out over more stitches than if the patch was not used, if failure occurs it will no longer be the pull tab stitches, but the patch stitches, making it round helps, making the patch bigger helps, using a patch on both sides wouldn't.
also, it's not really the stitches that are the weak link, but the needle holes that the stitches are pulling on, thus the more stitches/larger patch, the less pull on each stitch hole the stronger it is.
I had thought about sewing round patches on the front and the back of the tarp and then sewing on the pull out loop. That way the pull out will be sewn through three layers of fabric. I think that would be the strongest way to have them sewn on.
“Light thinks it travels faster than anything but it is wrong. No matter how fast light travels, it finds the darkness has always got there first, and is waiting for it." -Terry Pratchett
Premium Quality, Fresh Roasted Coffee
and using that method, i don't think you need anything really heroic or very heavy for the patches... just a little heaver fabric.
i'm sure you could guess from the photos that i sewed the grosgrain attachment strip to the outside patch before the patch was sewn to the tarp.
don`t leave the CREATOR out of the creation!
warbonnetguy is right - doesn't make any difference putting patches on both sides, you still have the same stitches supporting the load forces.