To get 2 cups of watermelon rind, you need 1/4 of a small watermelon.
Cut out the watermelon flesh, and save for another use.
Using a paring knife, remove all of the green skin from the watermelon rind.
Cut the rind into small, bite-size pieces, about 1/2-inch cubes.
In a small saucepan, combine the vinegar, water, sugar, salt, peppercorns, cinnamon stick, and cloves.
Bring to a boil over high heat.
Once it begins boiling, stir occasionally until the sugar and salt are dissolved.
Add watermelon rind cubes, and lower to a simmer.
Cook, stirring occasionally, until watermelon cubes are fork tender, about 8 minutes.
Transfer rind to either 1 pint jar or 2 half-pint jar.
Top with brining liquid.
Allow to cool for an hour before sealing with lids.
Refrigerate for at least 24 hours before serving.