Overgrips are used by tennis players - and because pickleball has the same kind of handle - overgrips are used by pickleball players as well. HERE is an informative video about the various types of overgrips used in tennis - which is informative for pickleball players because the same overgrips can be used.
An overgrip (also known as an overwrap) is a soft, padded, clothlike tape wrapped around the grip of a racquet. There are a few purposes for an overgrip. The two main uses are to add tackiness (stickiness) and to increase sweat absorption. Other purposes are for the expansion of the circumference of the grip, and for adding more padding or cushioning.
There are also different colors and patterns on overgrips for style and cosmetic alterations.
Some popular Overgrip brands are: Tourna Grip, ProKennex, Dunlop, Li-Ning, Gamma, Gosen, Head, Karakal, Prince, Völkl, Wilson, and Yonex.
Overgrips are generally applied from the bottom of the handle or 'butt cap' and up towards the throat (section between handle and head) of the racquet. It is wrapped around the handle overlapping by approximately 1/6 inch. If the overgrip exceeds the length of the handle and is at the throat area of the racquet, it is advised to cut the excess on an angle, and use grip finishing tape to keep it from unraveling.
To learn how to put on an overgrip, check out this video HERE.
For an extended video with a few more tips, check out it HERE.