Walking Through Tapes

This is an effective version of the double rope principle and coupled with showmanship it is very puzzling.

Two long tapes are freely shown and passed up under a gentleman's coat and behind him. One of the tapes is tied in a single knot in front of him to secure him still further. The ends of ropes are given to two spectators to hold, one standing at left, and other at right of gentleman who is bound. The latter is told to walk backwards with the result that the tapes instead of being behind him are now stretched in front. He has apparently walked through the two tapes.