From personal experience - two overgrips compete for title "thinnest" and tacky - Head XtremeSoft and Volk V-tac.
As mentioned in the previos posts, the overgrips are subject to additional thinning by tension, aplied while wrapping.
Pacific X-Tac is also susceptible to this manipulation ... exceptional feel !
Matter of choice...
Volkl X10 325, YPTP 53/50