Billabong Sol Mate Tank Top. Your new every-sunrise standby. The Sol Mate Tank is a soft woven layer in White Cap that looks like you borrowed it from a beach town market and never gave it back. Cut sleeveless with an easy, floaty drape, the viscose-modal blend feels cool against warm skin and tucks cleanly into cutoffs or skims over your favorite bikini bottoms. 61% Viscose 39% Modal. Hand wash. Imported.