American firm E Ink is exhibiting a prototype e-paper that is less than 300microns thick and displays four levels of greyscale at resolutions of up to 100 pixels per inch.

The 2,565mm display is built from Imaging Film, a fine steel foil with a white finish that can hold an image without a power supply.

Unlike Siemens' print-based flexible colour display for packaging, E Ink's product is based on thin-film transistor (TFT) technology, which is widely used in flat-screen computer monitors and TVs.

The display has already found interest among digital newspaper distributors.

David Owen, vice-president EMEA of Newspaper Direct, said: "We're getting ready for any channel that might or might not come in the future. We'd certainly use e-paper as a channel."

The e-paper, produced in partnership with Korean screen specialist LG Philips LCD, has not yet been given a date to go into production.