Japanese companies already use electrophoretic display, or EPD, for everything from watches and mobile phones to e-readers.

ZHANG: With Earth Day approaching and more companies looking to cash in on the "green" boom, electronic paper, already popular in Japan, may soon help eliminate waste, and turn a tidy profit, the world over.

Long predicted to replace traditional book or newspaper pulp, e-paper is not yet printing money, but tech firms hope its popularity may eventually mimic the real thing.

Japanese companies already use electrophoretic display, or EPD, for everything from watches and mobile phones to e-readers. Limited color, lower power use, and freedom from traditional paper are some of the attractions of the new technology.

E Ink, which manufactures the technology used in Sony's Reader tablet and Amazon's Kindle, says consumers will migrate to the technology based on higher paper and energy costs in an overall green push.

[Ryosuke Kuwada, V.P. Asia-Pacific Region, E-Ink]:

"The BRIC nations like India and China are consuming so much paper as their economies expand that the cost of A4 size paper is up 20-30%. As people try to wean paper use as soon as possible, the push for electronic paper is going to intensify."

EPD sends electronic charges along a grid embedded in the paper that cause tiny black and white particles to move, creating text and images.

E Ink is testing a color prototype, seen as key to opening the door to e-magazine and newspaper publishing and ultimately, a greater payday.