Hog Ring Pliers?

you can use any sharp object but most of the time you are not going through vinyl but the muslin (for lack of the correct term) type of fabric that the rods go through. you could still use hog rings on the edges but zipties are WAY easier to use on the center section of seat bottom and backs

Its been a few years and a lot of beers since I recovered a seat so my memory is vague.