Here's a tutorial that shows how traditional grommets are made.
Here's a video showing the same process.
The design shown on the left is made with a waxed thread whipping to bind the loose ends instead of the splicing shown in the tutorial.
I measure about 3 1/2 circumferences of cord then cut the piece and un-lay it. This creates three strands, each has a "corkscrew" shape due to the original construction of the cord.
As in in the tutorial above the cord is re-twisted in the circular form three times around. The ends are laid parallel and the whipping is applied.
A variety of sizes is available, this one is a 6" circumference. These are very sturdy and can be stretched hard to slip them over your hand. They will shrink back to original size or slightly smaller if you get them wet.
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