The dapper man in blue blazer and cordovan shoes gazes around the sun-dappled gallery as workers fit together a Crayola-colored Sol LeWitt sculpture. "This looks larger than when it was under construction," Raymond Perelman says, pleased by all he surveys, as well he should be.

The gem of an art deco building in which he stands - originally headquarters of the Fidelity Mutual Life Insurance Co. - was completed in 1927, a decade after his birth. This week it opens as the Ruth and Raymond G. Perelman Building; the Philadelphia Museum of Art's board of trustees chose the name after the couple pledged $15 million toward its purchase in 1999.

"It was a matter of perception. I knew we had to have it," says Perelman, 90, a museum trustee for more than 30 years who served as chair from 1997 to 2001 and now is chairman of its executive committee. "The building had come up for sale around 25 years earlier and we passed. Someone had to step up to the plate."

Though Perelman rarely grants interviews, he's hardly shy. He's a straight-talking, no-nonsense workaholic, a pistol who, by his estimation, has "bought and sold between 30 or 50 companies" in his lifetime, mostly old-fashioned manufacturing concerns. It's easy to sense that he's a bull when it comes to business.

"All successful people are risk-takers," he says. "And I always wanted to be successful."

Ruth, 86, is more retiring, a woman of few words, comfortable with letting her husband hold center court but quick to correct him when she disagrees. "I had a clue, though I had no idea he would be this successful," she says of her husband of 66 years. "He just felt he had to do these things. It's a fire in his belly."

"She's sort of the quiet authority," according to their older son, Ronald O. Perelman, the hugely successful New York financier.

"He can be tough. He's very persistent in his analysis," says Ron, 64, who first started watching his father at work when he was 12. "That's a quality we all have, both a plus and a minus."

He and Jeffrey, 58, worked for their father before going out on their own, both somewhat thwarted by his unwillingness to retire or relinquish majority control. Today Ron is the nation's 40th-richest citizen, worth $7 billion, according to Forbes magazine. Jeffrey, who lives in Wynnewood, runs his own holding company. All three Perelmans are in the business of buying and selling companies.

The elder Perelman does so with little sentiment - that's reserved for family. "I find companies where I see potential value," he says. But charity is where "you do things for other people, you want to give it back if you're productive. You can't take it with you, so you want to do the most good while you're here."

Says Ron, "From a very early age, it was made clear to us to help those who were in need and had less. It was instilled in us."

Ruth and Ray Perelman's gifts are made in both names; their myriad pieces of art were purchased by mutual consent. "There's very little they don't agree upon," Ron says. "She does have an enormous influence on him and what they do and give to and buy."

The Perelman building now joins the Kimmel Center's Perelman Theater, Penn's Raymond and Ruth Perelman Center for Advanced Medicine (currently under construction), and the Perelman Jewish Day School. In the last eight years, the two have publicly pledged more than $45 million in charitable gifts.

They oversee several foundations committed to community, education and the arts. How do they decide which one grants money to which charity? "Whichever foundation has the money in it at that time," Perelman says.

"They're wonderful partners," says Gail M. Harrity, the Philadelphia Museum of Art's chief operating officer. "Ray is . . . hard-working, involved, very driven and energetic and hands-on. Ruth is quieter but keenly aware and committed, sort of a wise counselor. Together, they're a fabulous duo."

The Perelmans raised their sons in Elkins Park before moving into town in 1970, to a duplex penthouse apartment with double-story windows facing north on Rittenhouse Square.

"I couldn't find an apartment the size I wanted, so I built this building," Perelman says. "You used to be able to see the Art Museum, but now the city is so built up you can only see a bit of it."

The light-filled space - as much art gallery and family archive as home - is beige throughout, the better to display their important art collection. His various awards are stashed in the wet bar.

Perelman reels off the artists as he points out their works - "Picasso, Renoir, Dufy, Léger, Braque, Noland, Botero, Friesz, Arp, Dubuffet, another Dubuffet." In the wood-paneled study, he stops before "my favorite painting. It's Ruth," perfectly framed in a halo of light, and near a small Renoir portrait of the painter's son Jean.

Every surface of every French antique is covered with silver-framed photos of their sons, seven grandchildren and five great-grandchildren. Jeffrey is long-married to Marsha, and has one daughter. Ruth can easily date celebratory images by which wife of the famously much-married "Ronnie" is in the photo. There have been four in all, including the late gossip columnist Claudia Cohen and famed beauties Patricia Duff and Ellen Barkin.

In the dining room, clothes are spread out from a recent three-week annual foray to Capri. The Perelmans spend six months a year at their Palm Beach home, and have a summer weekend place in Atlantic City.

This doesn't mean Perelman knows how to stop working. "None of us can relax," Ron says. "He's always on the phone to the office in Palm Beach."

Golf? "Never," Perelman says, swatting with his hand as if bothered by a fly. Tennis? Same reaction.

He goes to charity events, and Ruth loves to dress up, invariably in low-cut gowns that show off her extraordinary necklaces. That doesn't mean, however, that he likes benefits. "Have you ever had the food at these events?" he grimaces. So he's into food? "Let me put it this way: I eat to live."

Perelman's drive is innate. "My mother and father came here from Lithuania as teenagers with very little. They couldn't read or write English," he says. One of three siblings, he was raised in the Olney and Feltonville neighborhoods by his parents, Morris and Gennie. "My father was well-versed in Hebrew but had very little secular education. He went to school to learn how to write his name."

Even with little, the children were taught "to put a coin or two in the puschka, the charity box, for the Israel hospital."

Ray and his brother Leon went to work for their father, who looms large to this day. "He sort of fell into the business with his brother and an uncle - American Paper Products, a manufacturer of cylindrical cardboard tubes, like those for toilet paper but used for everything."

While working for the company in Greensboro, N.C., Ray was invited to a dinner the night before Yom Kippur and met Ruth Caplan of New Haven, Conn., a student at Greensboro Women's College. ("I wanted to attend Duke," she says, "but was discouraged because it was coed.")

Perelman made his first million buying and then liquidating Esslinger Premium Brewery at 10th and Callowhill. "You know what makes a beer 'premium'? Nothing but calling it that," he says.

Today, as chairman of Belmont Holdings Corp. and RGP Holding, Inc., Perelman has a net worth of many multiples of millions, though his businesses are private and the total value is known only to him and his accountants.

He holds to the immigrant ethos of keeping the business in the family and the family in the business. As he worked alongside his brother and for his father, so did his sons begin their careers learning from him. They went to Penn, as he did, and they have been active in philanthropy at their alma mater as well as in the arts. Penn's Perelman Quadrangle is named for Ron; Jeffrey and Marsha donated an oncology unit to Penn's Children's Hospital of Philadelphia.

Working for their father was not easy. "He was a great boss," Ron once said, adding, "I did get yelled at quite often." At age 35, he asked to be promoted from executive vice president to president - which he says his father saw as "an indication that he would be doing less. So we agreed to disagree," and Ron soon struck out on his own. Does he think this was in part the key to his success? "Oh, absolutely."

Jeffrey, too, asked his father to hand over the reins, in 1990, according to a 2003 Inquirer article. Instead, his father decided which companies Jeffrey could have to establish his own holding company.

Today, Raymond Perelman still goes to his nondescript Bala Cynwyd office most mornings when he's in town, his business invested in two commonly used minerals with multiple uses: diatomaceous earth and perlite ("the name's a coincidence").

He enjoys his success, and knows that with it comes responsibility. "I want to do things for people. I want to give back," he says. "If you're productive, and successful, that's what you're supposed to do."