Double-Sided Tape?

- Teacher, do you have some tape I could borrow?

- I got Scotch tape, Masking Tape, and double-sided tape.

- Hmmm, I'll take some double-sided tape.

- Here you go.

... he goes off for a couple of minutes and comes back ...

- Which side of the double-sided tape has the tape?

- It's double-sided tape.

... he stares at me ...

- So, which side?