"The idea was to sell anything that you had a good connection to buy," said Arnold Zaslow, at 82 the youngest brother.
The Zaslows' small-business experience is a remarkable and rare run for a family company, said Herbert J. Cohen, a partner in Executive Leaders Radio in Willow Grove, which offers syndicated programming.
"I've interviewed 2,000+ CEOs regarding their success, and I promise you the Zaslow story is special," Cohen wrote in an e-mail.
Far from its humble beginnings, ATD-American now has nearly 200 employees (counting a mill in Georgia, where 70 workers make sheets and pillowcases) and a customer base of more than 100,000 in 78 countries.
As a private company, ATD-American would not release its annual revenue, but it said sales had dipped since the 2008 economic meltdown that still has some of its institutional and government customers squeamish about spending.
Not that the Zaslow brothers are freaked out about it.
"I've seen it before," Arnold Zaslow said. "It will change."
It's a perspective unique to people his age, he said, explaining his lack of panic: "All you have to do is live long enough ... the same damn thing keeps happening."
He attributed the company's success, in part, to another piece of parental advice.
"Our parents always said you'll go farther if you stick together," Arnold said. Included in the Zaslow family seal is this line: "Union gives us strength."
The company started in 1931 as Jaffe's Art Linens in a storefront on South Street in Philadelphia, downstairs from the apartment where Irving and Ida Jaffe Zaslow raised their boys.
ATD-American now has 10 of the 40 Zaslow immediate-family members on its payroll. In a bit of torch-passing, third-generation Zaslows were elected to top management positions for the first time in 2005.
Jerome Zaslow's daughter Janet Wischnia, now 53, succeeded him as president of ATD-American. One of Spencer Zaslow's sons, Robert, 44, is co-president of the manufacturing operation in Georgia, Thomaston Mills; he shares the title with Wischnia's husband, Eric, 57.
On a recent morning at ATD-American's headquarters, Janet Wischnia and her cousin Robert were not nearly as laid back as their fathers.
"Growth is the challenge in this economy - trying to make sure we keep moving forward," Wischnia said. "I take the legacy really seriously."
In the old days, price ruled. Today, with the Internet enabling people to buy more easily from a wide array of suppliers, building relationships with customers is key, said Wischnia, an anthropology major at the University of Pennsylvania during "four years of rebellion" before getting an M.B.A. from Drexel University.
Robert Zaslow, a graduate of Penn's Wharton School like his father and uncles, suggested there were more things at play at ATD-American than a business-oriented gene pool.
"Given that the majority of family businesses fail by the 2nd generation and we are at the cusp of our 4th generation, we know that we have a very special business and culture," he wrote in an e-mail.
Six of the Zaslow brothers' nine children are actively involved in ATD-American. The other three - Arnold's two daughters and a son - are shareholders.
The hope is that at least some of the 18 who comprise the group the Zaslow brothers call Gen 4 - grandchildren ranging in age from 3 to 25 - will eventually join the company - not that their grandfathers are planning to retire.
Consider the following passage from The Time of My Life, written by Jerome Zaslow. It is a series of essays on business, family and personal achievements the oldest brother wrote over the years and published as a book in 2011.
"In no way do I expect to completely divorce myself from my life's work," Jerome wrote in the final chapter, "but I do expect to take more time to develop new ideas and opportunities for both the family and the company."
Thus the 87-year-old's current title of chief strategist and chairman of the board. Spencer, 84, and Arnold each serve as an executive vice president with specific areas of focus: operations for Spencer, financial/legal for Arnold.
That's an advisable arrangement, said Donna Marie DeCarolis, associate vice provost for entrepreneurship education at Drexel University.
Among the downsides of long-term involvement of principals in family owned businesses is "a tendency to avoid change, to shun new ways of doing things," DeCarolis said. "So from the get-go, openness, transparency and clear identification of roles and responsibilities is important when moving from generation to generation."
The Zaslow brothers' imprint on the business dates from when they were not yet teenagers and were working in their father's shop, where pillowcases sold for 8 cents and bleached sheets for 28 cents in 1932.
In 1947, with Jerome and Spencer Zaslow both through Wharton, they opened a second Jaffe's store at Broad Street and Olney Avenue. But dealing with picky female shoppers led Jerome to conclude that "it's not for me."
Back to his father he went for advice. They would close the two stores and shift to serving government and institutional customers.
In 1979, the brothers would relocate the company to Montgomery County, following a path similar to the one their parents took when they moved the family home from South Street to Melrose Park in 1947.
Today, a chandelier from that house hangs in a foyer just steps from their sons' offices.
The Zaslow brothers reveal their secret of working together for more than 75 years at their family business, ATD-American Co., which sells textile and furniture to institutional and governmental markets. Watch a video at philly.com/business.
Contact Diane Mastrull at 215-854-2466 or email@example.com, or @mastrud on Twitter.