I use a 2’ x 3’ piece of Tyvek. I stitched some loops of grosgrain ribbon to the corners so I can stake it down if I want to.
As others have shared, it is nice as a clean, dry place to step when getting into or out of the hammock.
One thing I don’t see mentioned: it is extremely helpful for keeping track of any gear I take out of my pack (or bin when car camping). Things don’t get lost on that white field as easily as they do in leaf litter - especially at night.
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