Intruder Alert!

Laser-only viewable images can be created so that they can only be seen when illuminated by a laser. This means that the average counterfeiter may or may not even realize the hidden message is present. "This creates a higher threshold of difficulty in duplication," said Kelem.

And of course, the quality of the substrate can distinguish a real hologram from a fake. "Often the difference in quality is enough to tell the real thing from the counterfeits," said Kelem.