In this activity, learners use Teflon (PTFE) tape to write secret messages. Learners may be familiar with Teflon-coated pans, but they probably do not know that Teflon is also made into tape that is used by plumbers. Teflon tape is great for plumbing because it stretches a little and makes a great seal, and since it is slippery, it makes pipes easier to screw together. Learners take advantage of Teflon tape's stretchiness to write secret messages. Use this activity to discuss the various types of polymer structures.