There is very little historical market information for the use of nanotechnology for writing codes and covert information. However, in a market report entitled "The Future of Nanotechnology in Printing and Packaging," from U.K.-based consultancy Pira Intl. (www.pira.co.uk), author Dexter Johnson estimates that the market will experience incredible growth over the next five years. To reach that conclusion, he uses the internal estimates of providers of nano bar codes ($500 million in 2007), along with demand surveys of those in the printing and packaging industries.

Printing and packaging respondents reportedly indicated that quantum dots and nanowires are the technologies they are targeting. Respondents were less enthusiastic about nano bar codes.

Johnson writes with more certainty about nanolithography, which is used by NanoInk and the National Physical Laboratory. But he points to their potential in more areas than just brand protection. He says potential markets for nanolithography include research labs, lab-on-a-chip systems for the pharmaceutical industry, making molds for soft lithography (or nanoprinting), and NanoElectroMechanical Systems (NEMS) for applications in resonators and wireless technology.

"The total market size of these applications is substantial," he writes. "NEMS could begin to make inroads into the $7-billion MEMS market, requiring more use of nanolithographic tools."