New technologies in fabrics have led to the growing industry of T-shirts, jackets and pants embedded with SPF to protect you from the sun's harmful rays. But there's no need to ditch your old wardrobe and buy pricey new high-tech fashions to have fun in the sun: You can wash SPF protection right into your existing wardrobe. SunGuard RIT is an additive you combine with laundry detergent that leaves a safe, active ingredient on the fibers of your clothes. It blocks up to 96 percent of the sun's harmful rays and has an equivalency of an SPF 30. One coating will withstand 20 future washings.