Jump to content United States-English
HP.com Home Products and Services Support and Drivers Solutions How to Buy
» Contact HP

HP.com home


Commercial printing's next big thing

It's all digital, all the time


HP Labs

» Research
» News and events
» Technical reports
» About HP Labs
» Careers @ HP Labs
» Worldwide sites
» Downloads

HP color ink

Indigo Lab
Content starts here
We're about removing the technical barriers so HP can be even more successful in the industry.

By Jamie Beckett, Jan. 2006

It was a sunny afternoon in 1999 when Eric Hanson gazed across a conference table in Rehovot, Israel, and wondered if he was looking at HP’s next big printing technology.

As a researcher in HP Labs, Hanson had helped develop thermal inkjet printing technology and watched it grow into a multi-billion dollar business. He'd seen HP's laser printing business become a market leader.

Now he listened as engineers from Indigo N.V. described their unique process for using digital technology for producing high-quality, short-run prints at a fraction of the cost of traditional offset printing.

Shortly afterward, the two companies entered into an alliance (HP later purchased Indigo) and began the process of merging Indigo's technology with HP's digital color printing systems expertise. The goal: to transform the commercial printing industry – now dominated by traditional offset lithography presses – into an all-digital, Web-enabled business.

Applied research

With that task in mind, Hanson set his team to work. One scientist went back to school to learn how to operate a printing press. Others investigated the machine's printing process and color consistency. HP Labs even purchased a press and installed it in HP's Literature Distribution Center to compare Indigo's print-on-demand capability with the old system of warehousing of preprinted materials.

Across the globe in Haifa, Israel, a crack team of HP Labs mathematicians – researchers who'd already contributed to nearly all of HP's recent scanners and cameras – began working their algorithmic magic on improving the presses' image quality and efficiency.

Their efforts paid off a year ago when the company released the HP Indigo Press 5000, the first in the line to benefit from HP Labs' innovations. These include improvements in paper handling, color management and waste reduction, and future generations of the presses will include much more.

The team's long-term goal is to automate as many of the Indigo's processes as possible to lower cost, increase speed and image quality, and simplify press operation.

"People assume that offset presses set the standard for high-quality printing, but we disagree," Hanson says. "If we keep pushing the technology, we think digital will win."

How well are they doing? Here's what the respected publishing-systems experts at The Seybold Report had to say in July 2005: "Many printer manufacturers argue that their equipment can deliver either 'offset quality' or 'almost offset quality.' HP makes this claim in its marketing. In the case of the Indigo 5000, we would be inclined to agree."

Here is the story of how they got this far, and a peek at some of what's to come.

» Unique technology
» Getting it right
» The Israel connection
» HP's press shop
» The science of great color
» What's ahead

Unique technology 

In offset printing, ink is spread on a metal plate with images formed in a polymer layer on its surface, then transferred to a rubber blanket, which applies the image to paper. Because setting up each job requires considerable time and expense, it is most commonly used for large press runs of items like newspapers or catalogues.

Indigo's unique technology, called Liquid Electrophotography (or LEP), combines digital laser imaging, ultra-small ink particles and a liquid transport system to produce prints comparable to offset quality.

Because it is digital, the system can do short-run printing much more cost-effectively than offset, even personalizing each document, which is not practical with offset.

Because it uses liquid ink, it can rival offset's quality and speed. By comparison, the dry toner (that black powder you see when you change the cartridge on your laser printer) used in other digital presses can be difficult to control at high speeds.

"It's like driving on an unpaved road," says Omer Gila, who managed color control at Indigo before joining HP Labs in 2001. "Powder produces clouds of dust which degrade image quality. To reduce the clouds, you have to go more slowly. Or, on a press, you have to use larger particles."

HP Indigo presses solve this problem by containing the particles with the surface tension of liquid ink, Gila explains.

Getting it right 

Yet LEP technology is not without its challenges. For one thing, it requires so many elements – materials, mechanical adjustments, voltages, temperatures, etc. – to come together in exactly the right way. That means work for the press operator, who also has to attend to paper jams, monitor print quality, maintain the machine, and lots more.

"When we first looked at the Indigo system, there were more than 30 different adjustments on the paper-feed unit alone," says Bill Holland, a researcher at HP Labs who has been working on Indigo technology since 1999. "So the first thing that occurred to us was to focus on improving the ease of use and reducing the cost of the machines."

Researchers had plenty of experience developing easy-to-use digital color-printing systems, but as Hanson puts it, big presses were "uncharted territory."

Michael Lee, who holds a PhD in physics, volunteered to take two training classes for Indigo press operators. He, Holland and others on the team poured over the Indigo service manuals to figure out how difficult maintenance was. Researchers scrutinized individual components of the presses, eventually adding such functions as recycling for imaging oil, and improving sensors for paper thickness and ink density.

In the process, they got to know the Indigo technology very, very well.

"Labs worked on everything – the underlying chemistry, the mechanics, the electronics, the imaging pipeline and more," recalls researcher Keith Moore, who joined the effort in 2004. "We're about removing the technical barriers so HP can be even more successful in the industry."

Israel connection 

At the same time, researchers in HP Labs Israel were getting to know Indigo technology in another way. Long accustomed to working across languages, time zones and distance with U.S. customers, the team began what became a warm and productive relationship with their counterparts at Indigo, who were located less than two hours away from the Haifa lab.

Scientists delighted in the spontaneity of being able to make a quick telephone call or hop on a train to brainstorm, test ideas and experiment.

"Having a business customer so close makes all the difference," says Doron Shaked, who leads one of two HP Labs Indigo research teams. "Some of us know the presses very intimately by now."

"We speak the same language, and I don't mean just Hebrew," adds researcher Mani Fischer. "We understand how things happen, how the presses operate, and we understand how we can help each other."

The algorithm group

That closeness worked. Shaked's team contributed technologies that make it easier for press operators to monitor and inspect in-progress jobs and print more consistent pages. They also provided capabilities that give customers the flexibility to balance print speed and image quality for best results.

A team lead by Carl Staelin, a principal research scientist in HP Labs Israel, developed a less expensive and more efficient method to measure color consistency and improve print quality.

"Indigo's engineers would raise a problem they thought we might be able to help them with, and people in our group tried to catch whatever we could," he says.

Adds Pinni Perlmutter, chief technology officer for HP's Indigo Division: "We feel they're a part of us. We look at them as our algorithm group. If you need some sophisticated, state-of-the-art algorithm to solve any problem, these people are our first choice."

HP's press shop 

Sometimes there's no substitute for getting your hands dirty. After HP acquired Indigo N.V. in 2002, the HP Labs set up its own print shop to give researchers the ability to experiment on working Indigo presses. The shop currently houses four presses, including the HP Indigo Press 5000, and is staffed by two trained technicians who gather data, assist in analyzing it, and help to set up and run experiments.

These experiments require incredible control because each press component is interrelated, explains Paul Matheson, an electronic prepress technician (prepress is the file-preparation side of printing) who joined HP Labs in 2002.

"It's a very multi-disciplinary problem that involves electrical, physical, chemical and mechanical processes. You change one and it affects all of them," he says. "If someone is investigating the press blanket, you have to consider the paper, the temperature of the ink, the materials that make up the blanket, the chemicals in the ink – everything."

The science of great color 

When it comes color printing, Gary Dispoto doesn't like surprises. He wants users to get the results they expect and he wants the color to "just work." He and his team at HP Labs have devoted the past two years to trying to make sure that's what happens with HP Indigo presses.

We've all had the experience of seeing a color on our computer screens that doesn't show up on the printout, or seeing color differ from one printer to another. That happens because devices differ in the range of colors they can reproduce.

Dispoto and his team have made color management more predictable by working with the International Color Consortium (ICC) to establish and improve standards for color communication and transforms. Color profiles contain the information necessary for colors captured on one device to be reproduced satisfactorily on others.

"We've worked a lot in this area because we're trying to get the best possible print," Dispoto explains.

Similar thinking led to the development of CMYK (Cyan, Magenta, Yellow, Black) Plus, a rendering technology that makes color appear consistent across different HP printing devices while still using each device's fullest color capability.

With CMYK Plus, users get the full, rich colors they expect from their printer while getting consistent results no matter what HP printer they use, explains Dispoto, whose team contributed to the technology.

On the HP Indigo Press, CMYK Plus adapts lightness and maximizes color saturation to make the most of the range of colors the printer can reproduce.

All digital

By making color management more predictable, researchers hope to help transform commercial printing into a Web-based business. In the past, a graphic artist working on a magazine cover would have a proof made and take it physically to a printing shop where a press operator would adjust the press until the printout matched the artist's proof.

"When press runs were long – that is, many thousands of prints – it was worth it for the graphic artist to hand-carry documents and for the press operator to spend lots of time making adjustments," Dispoto says. "Today marketing collateral is becoming more personalized and short-run printing is more common. You can't afford to have someone twiddle knobs on the press. It has to work more automatically than it did."

Instead, the graphic artist should be able to create a design, proof it on his or her own HP DesignJet, send it by e-mail to the printer – and be assured that the final product will match the proof. The ICC color management system now has this type of capability due to the leadership provided by HP researchers.

What's ahead 

In the early days of HP's involvement with Indigo, Perlmutter recalls how engineers spent a lot of time together figuring out in which direction they wanted the technology to go.

"We looked at what areas we wanted to improve," he says. "We talked about what our 'dream machine' might look like."

They're still working toward that dream machine. Only now, instead of a handful of engineers in a small conference room, there's an entire technical community inside HP – in Haifa and Rehovot, and in Boise, San Diego and Palo Alto – thinking and working daily to design a digital commercial printing system that not only beats all other digital presses, but also beats offset.

" We're not quite there yet," Hanson says. "But we think we can nail it."

Jamie Beckett is managing editor of this Web site and a former reporter and editor at the San Francisco Chronicle.

Related links

» HP Commercial printing
» HP Indigo Press 5000

News and events

» Recent news stories
» Archived news stories

Indigo print samples

Bill Holland

Printable version
Privacy statement Using this site means you accept its terms Feedback to HP Labs
© 2009 Hewlett-Packard Development Company, L.P.