Waterproof picnic blanket vs tarp: Tarp wins for beach and sand use

Don’t waterproof a fabric blanket—the coating wears off fast from sand abrasion and moisture still wicks through. A cheap polyethylene tarp is actually waterproof, sand shakes right off, and it’s lightweight. Throw a thin blanket on top for softness. If you want one blanket to do everything, buy a dedicated waterproof picnic blanket with a bonded backing for about $30.