Used for hard to repair cracks where paper tape has failed. 4 times stronger than paper tape. Will not blister, tear, crack, or fuzz-up during sanding, and holds straight line. Waterproof, use in wet areas around tub and shower enclosures where moisture lifts or pops paper tape. Material can be second coated immediately. Tuff-Tape is an ultra thin version of Strait-Flex Original drywall corner tape made of high tech composite material. Installation does not require fasteners or stapling.