New homes, new shops and new industries are spreading across Northern Virginia as the frontiers of growth move steadily outward through Fairfax, Prince William and Loudoun counties.

When the National Geographic Society sends membership certificates to its annual crop of more than 1.5 million new members, hundreds of housewives around Woodbridge spring into action.

Much of the typing, folding, collating, inserting, sealing, addressing, sorting and bundling is done at home in an organized cottage industry by homemakers, primarily wives of men who work at the U.S. Army's Fort Belvoir or the U.S. Marine Corps base at Quantico. The final stamping and sorting is done in a new Prince William County warehouse that can process more than 1 million pieces a day of "what some people call junk mail," according to Lon Bond Persley.

Persely and his wife, Kay, head Bond Office Services Inc., which Prince William county recently lured from Fairfax. It is part of the vast mailing industry here that last month alone produced more than 150 million pieces of bulk mail with a Washington postmark.

Persley's 25 full-time employes and 300 part-time homemakers, working in one of the area's largest direct-mail companies, have sent up to 17 million mailings at a time for government agencies, political candidates, fund-raisers and profit and nonprofit groups.

For a Christmas sales promotion, the firm sent 8 million letters, done largely by machine, although Persley believes his brigade of housewives is the "largest group of handworkers" in the bulk-mailing trade. The part-time workers are paid the minimum wage, $2.90 per hour, which will rise to $3.10 in January. While the wage sounds low, Persley says the work is done at home, making it easy for the women to work it around their own schedules, and involves no time or money for transportation. In addition, Persley's firm supplies the women with all the equipment they need, such as special electric typewriters.

"I've heard people say there are now more than 10,000 companies around Washington that support themselves solely by contributions from direct mail. Just look at the Yellow Pages," said Persley, quickly counting more than 45 mailing-list companies in the metropolitan area, 50 direct-mail companies, 50 letter shops and some 75 addressing and letter service companies. cWashington's downtown post office lists about 7,000 bulk mailers.

Moving to the Washington's outer suburbs has added little time or distance from Washington, Persley says, because his plant is beside I-95. The move also made it possible for him to buy land much more cheaply, he said, in a county with a better labor market and lower tax rate than Fairfax.

Another reason Bond Office Services Inc. was seduced away from Fairfax in the highly competitive city-county battle to attract new businesses was the low interest on a loan of as much as $1 million that the Prince William Industrial Development Authority dangled in front of Persley.

Persley, a former military and commercial pilot who also test-piloted jets, got into the mailing business when he was passing through Washington half a dozen years ago to get a passport for a pilot's job with an African airline. aHe met some friends with a letter service company here who convinced him to stay and join the firm.

"I only learned later that they were having trouble with the U.S. Department of Labor and the company was going bankrupt . . . but I saw the possibilities in the business," Persley said this week while sitting in the office of his 2-month-old plant. Above his desk hangs a photograph of Persley and the Jimmy Doolittle plane that bombed Tokyo, which Persley later flew.

Persley and his wife, who is the company's market manager and also drove a giant dump truck to haul more than 300,000 tons of gravel for the new plant site, originally started their company in a tiny Woodbridge warehouse where all work was done by hand. They soon moved across the Fairfax County line to Lorton, where they could found larger warehouses to rent. "But we were spending $50,000 a year to rent four warehouses, and I said to myself, 'we can build our own plant for that,'" Persley recalled.

Land prices inside the Beltway forced Persley to look in Washington's outer suburbs and "exurbs," as planners now call the far-out metropolitan fringe of Washington where much of the current housing and industrial boom is occurring.

The Persleys found what seemed a perfect spot on three acres at the Dale City exit of I-95. The site is part of the Northern Virginia Industrial Park, one of several industrial parks Prince William County has created near its two airports industrial parks Prince William County has created near its two airports (Manassas and Woodbridge), two railroad lines (Southern and Richmond, Fredericksburg & Potomac) and two major interstates (I-66 and I-95).

Fairfax County, which is enjoying the fastest industrial growth in Northern Virginia -- adding 14,000 jobs and 1,413 companies to the county's tax rolls in the past two years -- showed little interest in keeping his company, Persley said, except to ask him to join the county Chamber of Commerce. "Which I did anyway," said Persley.

Prince William, on the other hand, was anxious to find Persley an industrial home and bring jobs to the county -- only 27 percent of Prince William's population works within the county -- and the county's 6-year-old industrial authority quickly gave him a $1 million "inducement resolution," the second one granted since the authority was created in 1973.

Under the federal-state program to encourage industrial development, banks can loan up to $10 million to firms given inducement resolutions and pay no state or federal taxes on the interest. Thus the banks usually loan money to such firms at lower-than-normal interest rates.

In addition to the $700,000 it cost to build his plant, Persley spent another $275,000 to improve his equipment, because "in this highly competitive feast-or-famine business you have to be able to do 1 million pieces a day."

For instance, on a mailing of 1 million first-class letters, Persley said, postage will run $150,000, printing cost another $150,000 (paid by the client) "and we get about $75,000 . . . not very much when you consider we've barely raised our prices now for almost six years."

The Persleys say their company turns down no mailings, except pornography, and has done work for many political campaigns and liberal and conservative groups, groups whose names they don't reveal, "although the National Geographic Society lets us mention theirs," said Persley.

"But it's a chicken-or-egg business.Which comes first? Do you get the machines and then the business (his 16 sorting machines cost $25,000 each) or do you seek the business first?"

The Persleys acquired the nest eggs first, and their assembly line in Prince William. Although their home is an hour's drive away in Warrenton, one of their twin-engine pleasures is nearby at Woodbridge Airport, where Kay Persley, adept at managing sales and dump trucks, is now learning to fly. k