A friend of mine is designing the costumes for Sweeney Todd, and she needs some of the costumes to shine at one point to make the characters look like memories or ghosts. She's read about the scotchlite beads that 3M makes and is wondering if they can be mixed with paint to paint the costumes so that they look normal under some light but gleam and glow under different light. Please let me know if you have used anything like this before. ps. I'm the lighting designer for the same production so if it requires some specific lighting effect that's fine, I can hook her up...