Well, they're not grommets, Walmart sells them as 'extra large eyelets' (much cheaper than the grommet kit they sell in sporting goods). I've tried 1 layer of ripstop, 2 layers, 1 layer of webbing, 2 layers of webbing, every time i've attached one, i've tied a cord into the grommet and pulled pretty hard to test it's strength. Every method I have tried so far has had the fabric bunch up in the direction of pull, and pull away from the hole and enlarge it opposite the direction of pull. None of this is satisfactory. These eyelets are the ones with metal 'fingers' that bend and lock the piece in place, as opposed to the normal camping grommets which are smooth metal all around, not sure if it matters. Maybe i'm not hammering them in enough. Not sure which part of the grommet is supposed to have the holding power.
What type of grommets/eyelets have you used for your tie-outs? What type of reinforcement? Any tricks?