Originally Posted by exup
I think the grosgrain adds strength and takes some of the strain off of the nylon.
One thought... If silnylon stretches more than polyester, that means the silnylon's stretch would outpace the polyseter edging's stretch over time, thus causing slack in the silnylon. When joining materials, if properties vary widely, issues occur at the joins.
Tarps tend to be handled more at the edges? Yes? No? The only benefit I can think of edging a tarp is sudden yank/pull protection. If the goal is to spread out the force of tensioning through the edging, then edging makes sense. But that doesn't explain the lack of a ridge edge.
I'm thinking it's mostly aesthetic. This tarp has a definite cool factor other minimalist tarps lack. It has a lot to do with the color contrast of that edging.
To be clear, is that edging material polyester? It does appear thicker than nylon. I've found some close up shots, but not close enough to tell for sure.