LEWISVILLE, Texas - Archivists responsible for putting together the presidential library of former President George W. Bush will have to process 80 terabytes of electronic information - 20 times the Clinton administration's 4 terabytes.

Bush's electronic archives contain 200 million e-mails, compared with 20 million in former President Bill Clinton's. Bush's archives also include share drives, hard drives, scheduling systems, and digital photography, which his administration switched to about halfway through his tenure.

The average size of a quality digital photo is 3 megabytes, meaning just one terabyte can store more than 300,000 such pictures.

The Bush administration e-mail alone would take up an estimated 600 million printed pages, said Alan Lowe, director of Bush's presidential library and museum.

Combined with 70 million paper documents, the haul eclipses the 550 to 580 million printed pages Lowe estimates are in all other National Archives' presidential libraries.

"In the old days, the National Archives went in and packed up trucks and trucks full of paper," Lowe said.

The preponderance of electronic files presents new challenges, ranging from dealing with the sheer volume to ensuring consistent redacting of information in an e-mail chain that may have been extended dozens of times.

Lockheed Martin Corp. has created an electronic records archives system for the National Archives that is designed to preserve the federal government's digital records. Lowe said the system is designed to ensure that digital files will be accessible as computer programs evolve.

"It's not dependent on any sort of operating system that we're using right now," he said.

Bush archivists already have the ability to search the system and retrieve documents. Now they must begin processing the data, reading through each document to decide what might need to be redacted for personal or national security reasons. They'll also put specific topic designators on documents to make them easier to find.

On Jan. 20, 2014 - five years to the date after Bush left office - citizens will be able to request access to his administration's archives through the Freedom of Information Act.

In anticipation, Lowe said, archivists already have started processing the administration's paper records and will start on electronic files in the next year, when the new system has finalized redacting capabilities.

Lowe said processing all the records ultimately will take decades, but some records also will be handled as requests come in.

"It's going to take a long time," Lowe said.

It's slow going even without electronic files. National Archives' staff noted in an article in the Public Historian that Ronald Reagan's presidential library processed only 9 percent of its records in the five years after he left office, while George H.W. Bush's got through 7 percent.

Presidential archives in any form offer insight into an administration and can shed light on how policies developed, said Bruce Buchanan, a professor of government specializing in presidential studies at the University of Texas at Austin.

"If you assemble these archives and interpret them carefully, you can come to understand how a president makes decisions," Buchanan said.

But he said e-mail was new enough that until the archives could be accessed, it remained difficult to say how much additional insight could be gained from it. Much will depend also on researchers' patience.

"It's going to take lots of sifting and interpreting," he said.

Former Bush adviser Karen Hughes said although they were told in initial staff meetings that all correspondence eventually would be public, "it's not something you think about every time you send an e-mail."

Still, she said, the most important conversations and decisions took place in face-to-face meetings with the president.

The George W. Bush Presidential Center - including the library, the museum, and a policy institute - is set to open in February 2013 on the campus of Southern Methodist University in Dallas.

Until then, the archives are being kept at a warehouse in the Dallas suburb of Lewisville.

Aside from electronic and paper files, the archives also will include 42,000 artifacts, ranging from the bullhorn Bush used when visiting ground zero days after Sept. 11, 2001, to lavish gifts from foreign heads of state.

The archives will include records from everyone who was part of the Executive Office of the President, but don't expect to see e-mail from Bush himself.

The former president said during an interview at Facebook's headquarters that he didn't use the technology.

"I didn't want any of those [e-mail messages] to be mine," he said. "The problem is that if you were to read some of my e-mails, today you can read anything you want into them."