Grommets are metal or rubber rings that make the edges of a hole in a piece of fabric or plastic stronger so that the hole does not tear with use. Tarps that are made to be tied down over whatever item they are protecting need grommets in their corners so that the twine or rope that is threaded through the holes does not cut into the sides of the holes or tear the hole out. Use grommets to guard against tearing the tie-down holes. Grommets are most easily set with grommet pliers, which function the same way for fabric or plastic tarps.
Things You'll Need
Mark the intended hole locations on the tarp with a pen if the holes are not already made.
Place the grommet pliers, which look much like a hole punch, over the mark for the intended hole. Place the bottom half the grommet, open side up, on the bottom holder surface of the pliers.
Place the top half of the grommet, open side down, centered over the hole mark. Carefully squeeze the pliers until the top holder surface of the pliers touches the top grommet half to make sure the pliers are centered over the two grommet halves.
Squeeze the pliers tightly and hold for two or three seconds as the top and bottom grommet halves are squeezed and pinched together, making a full grommet.
Remove the fabric from the center of the completed grommet, which is usually cut out during the process of pinching the two grommet halves together.
Use the instructions on the back of the grommet package to help identify the top and bottom halves of the grommet if necessary.
Squeeze the pliers together as hard as possible when setting the grommet to give the best chance possible of a complete pinching together of the two halves, as removing an improperly-set grommet is very difficult and often makes a mess of the tarp.