Today, when a print cartridge runs dry, consumers just buy more ink, not an entire new print head.

FORBES: HP Finally Delivers On 'Invent'

The new manufacturing process allows HP to fit 3, 900 or more microscopic ink nozzles on a single print head, compared to 1, 266 nozzles on past designs.

FORBES: HP Finally Delivers On 'Invent'

And because the company uses capsules rather than beads, it can mix them with a binding agent and print its electronic ink on to almost any surface, just as though it were real ink.

ECONOMIST: Showing off

Finally, when the block is ready to be used, it is covered with ink and pressed by hand onto paper to print the final image.

UNESCO: Culture

Black ink costs about 4 cents a page while you can print a page of color for about 7 cents.

FORBES: Small and Affordable Brother Multifunction Device Prints 11 x 17-inch pages

If a customer gripes that its telephone book is light on ink, Daly can look at a report on the print run and, if he sees that the last 1% of the run wasn't dark enough, tell the client to open another box because the rest of the run was fine.

FORBES: Companies & Strategies

Designed for portability, the Z340 combines a 14.0 megapixel digital camera with a ZINK-enabled printer using the ink-free Zero Ink Printing Technology from ZINK Imaging to deliver a 3x4'' print - the same size as the classic Polaroid photos that captured millions of special memories over the past 63 years.

ENGADGET: Polaroid releases Z340 Instant Digital Camera, Gaga's Grey Label snapper still on the edge of glory

T-Ink Chief Executive Martin Abrams says his company is trying to figure out how to print a power source and speakers, too.

FORBES: Touchy Circuits