On a bank of the Mohawk River, a windowless industrial building of corrugated steel hides something that could make floor lamps, bedside lamps, wall sconces and nearly every other household lamp obsolete.

It's a machine that prints lights.

The size of a semitrailer, it coats an 8-inch wide plastic film with chemicals, then seals them with a layer of metal foil. Apply electric current to the resulting sheet, and it lights up with a blue-white glow.

You could tack that sheet to a wall, wrap it around a pillar or even take a translucent version and tape it to your windows. Unlike practically every other source of lighting, you wouldn't need a lamp or conventional fixture for these sheets, though you would need to plug them into an outlet.

The sheets owe their luminance to compounds known as organic light-emitting diodes, or OLEDs. While there are plenty of problems to be worked out with the technology, it's not the dream of a wild-eyed startup.

OLEDs are beginning to be used in TVs and cell-phone displays, and big names like Siemens and Philips are throwing their weight behind the technology to make it a lighting source as well. The OLED printer was made by General Electric Co. on its sprawling research campus here in upstate New York. It's not far from where a GE physicist figured out a practical way to use tungsten metal as the filament in a regular light bulb. That's still used today, nearly a century later.

The invention of the incandescent bulb created the pattern for home lighting: Our light sources are small and bright. Maybe there are a few in the center of the ceiling, and a few in the corners of the room. Because they're too bright to look at, they need to be reflected and diffused with lamp shades and frosted glass.

OLEDs could overturn all that, with broad, diffuse light sources bathing rooms in a gentle glow. Photographers go to great lengths to diffuse the illumination they use when shooting portraits, because they know we look our best in soft light.

The big glowing sheets could also make light sources out of everyday things. GE imagines putting OLEDs on the inside of window blinds — pull them down, light them up, and you have light streaming from the window, even at night. You could even make OLED wallpaper, since the material is flexible.

"We have a lot of ideas for what we can do with it," said German lighting designer Ingo Maurer.

He and his firm have already created the first commercially available OLED lamp, and is selling it in a limited edition of 25. He expects to deliver the first two this month, at an undisclosed but presumably collector-level price. The lamp is more of a curiosity than a practical product: the light is dim, and gradually grows dimmer, losing half its brightness after 2,000 hours. Its OLED panels are only a few inches wide, and made of glass rather than plastic. They protrude from a central stem like the leaves of a fern.

The panels in Maurer's lamp are made by Osram Opto Semiconductors, a subsidiary of German industrial conglomerate Siemens AG, which is also the parent of Osram Sylvania, a competitor to GE in the general lighting market.

Osram Opto made them with an expensive, slow process known as vacuum deposition that has dominated OLED development so far. One virtue of this method is that it can be combined with the technologies that produce LCD displays to make full-color OLED TVs. Sony Corp. sells an 11-inch model for $2,500.

OLED TVs have to become much cheaper (and larger) to become mass-market products, and OLED lights have to be cheaper still. That's the issue GE is tackling with its printer, which dispenses with vacuum deposition in favor of a process that's not much more complicated than the printing of a newspaper.