Crab Flour Sack Towel. Blue Ocean Crab Cotton Flour Sack Towel - 23163 - features a Blue Crab design - old fashioned, multi-purpose flour sack towel is made of 100% cotton. It measures approx 18" x 28". Lint free, long lasting, soft & durable, absorbent. Bring the beach to your home wherever you need a hand towel.