Water Soluble Paper, White, 15-1/2 in x 165 ft x 0.0035 in. Provides a convenient and cost effective method for creating purge chambers for pipe welding. Low air permeable purge gas barrier for TIG welding. Excellent barrier for retaining noble gas (argon and argon/helium mix). Simple and fast construction. Dissolves effortlessly and rapidly during water or steam hydro-test, leaving no residue in pipeline.