Attention shoppers! This display made with electronic ink!

Digital ink has, for years, been hailed as a potential savior of the book industry -- a revolutionizing technology that would change the way we would both print and read.

Wired Magazine, in one of two pantingly eager features on digital ink in 1997, described it as
"an invention that revolutionizes publishing and threatens the global paper industry. Something so basic yet so flexible, it changes everything from books and newspapers to wallpaper and package design." Nicholas Negroponte, also in Wired, pontificated that "paper is a medium for the future. A medium that will build on its current ubiquity, but in an exciting and revolutionary way."

After years of such hype, this medium of the future has arrived. E Ink, the digital ink company
that emerged from the MIT Media Lab's
"Things That Think" project, on Monday proudly debuted its first commercial venture.

The revolutionary product? An advertising display for J.C. Penney.

A 6-foot-long, 3-millimeter-thick curving sign will hang over the "Simply for Sports" counter at the J.C. Penney store in Marlborough, Mass., to promote products and special deals. It looks like paper but weighs 8.7 pounds, and its message will change every 10 seconds. Plus, J.C. Penney employees can update multiple signs using a single pager.

This revolutionary signage is made possible by E Ink's technology, Immedia, which is based on a microscopically thin coating of particles and conductive tracing that is applied to paper. When an electric charge is applied to the coating, those particles change colors to create white and blue words.

Digital ink may well be a cheaper, easier, more utilitarian way to advertise products. Still, signage is a bit of a disappointing first product for those anxiously awaiting the ink that was supposed to change our literary lives. An ad for T-shirts at J.C. Penney, after all, doesn't quite offer the enlightenment value of a digitally delivered "Tristram Shandy."

"It's not as cool as an electronic book," admits J.D. Albert, a founder -- along with Barrett Comiskey -- of E Ink. "It plays into a lot of the advantages of the ink while also being a pretty practical thing to do today. It's easy for us to do large cheap things with big pixels," he explains, whereas a book requires smaller, higher-resolution technology. Digital ink books, he says, are another three to five years away.

But the E Ink founders aren't going to complain about their current market: After all, as Negroponte pointed out in his Wired article, the market for flat-panel displays in 1997 was $30 billion per year. The cost for one of E Ink's displays is $500 to $5,000, depending on size, and Albert and Comiskey assert that there has been lots of interest in the product.

Who knows? Maybe such ad-based revenues will hasten the delivery of those digital books to the electronically impoverished literati.