Pipe dope is a gooey paste that is used on threaded pipe joints. Teflon tape is used for the same purpose, and some plumbers use both at the same time.Plumbers putty is use when installing sink drains.y personal, repeat personal, preference is pipe dope on water and gas joints, Teflon tape on air fittings. There are two grades of Teflon tape, the familiar white tape for water and the less familiar yellow for gas. The yellow is thicker than white.