Polytetrafluoroethylene (PTFE) Thread Seal Tape. Widely used by plumbers for General Water Plumbing applications. Housed in a convenient blue spool and white cap, making it easy to use. PTFE has the lowest coefficient of friction of any known solid material and is very non-reactive. Therefore, it is compatible with a very wide range of materials. PTFE Thread Seal Tape is a modern material for all conventional pipe dopes. It can effectively alleviate many of your piping headaches, while substantially reducing piping cost and maintenance.