This trick is not for walk around. Better as a one time effect done at a party or show, or for
friends. Requires set up, but not a lot and you need to do the effect shortly after set up. Too
much time, and other considerations, can cause the effect to not work. Cannot say what they are
without giving away the trick. Just know that some things will make the effect not work.
All that being said, if you set up before you start and do it within a reasonable time and avoid
certain situations, you will have a very visual and startling effect that is a big hit with the
audience.