Add up all the restaurant tablecloths, hospital bedsheets and work uniforms that people use every day, and you get a linen industry that has to track billions of items. New materials developed by Brown University physicist Nabil Lawandy may stream-line this task.

The materials return specific frequencies of light when struck by a laser beam. Putting an array of threads spun from this material into the border of a tablecloth or the label of a garment results in a "smart textile" that identifies itself optically under laser illumination. The threads are faster to read and more durable than the bar codes and radio chips now used for identification. Spectra Science of Providence, R.I., has formed a textile-manufacturing division called Millennium Textiles to commercialize the new material.