Walt, I'll take a stab at it...you can also try seaching for "tarp buttons" - that's where IaW and others have taken small rocks, nuts, etc...and used them instead of using the grommets - eliminating the weak point.
I've used a small stick myself when using the grommets - especially if I'm expecting a very windy nite. the stick spreads the 'pull' to the entire length of your stick. 4-6 inches is usually plenty for me...and if I have lots of time to make the stick "pretty" - I'll shave the bark to make it smooth, and round the ends.... protecting my tarp. tie your string/cord/etc...to the stick....on the inside of the grommet.
it's a highly effective way to save a tarp from ripping out at a grommet point.
if that's what you are asking about.... lol. :7: