Jasper Johns in his Connecticut studio. Photograph by Jeff Riedel

Not all gallerists share this knack. Tony Shafrazi, for example, used to visit the painter Philip Smith in his studio, and, if he wasn’t impressed with what his client was doing, take a paintbrush to Smith’s works-in-progress, to demonstrate how to improve them. Donald Baechler, who remains close to Shafrazi and is happy to work with him, recalls, “Tony used to call my studio and give me advice on how to paint. I’d put the phone down and keep painting, and when I picked it up fifteen minutes later, he’d still be talking.”

Marks’s extremely user-friendly approach to representing artists also serves as a useful recruitment tactic. “I don’t discover artists,” Marks says. “Almost all of my artists showed with somebody else before they came to me. So, obviously, they left because, wherever they were, that place was not doing what they were supposed to do. I spend a large part of my day on the phone with them from home just making sure they’re taken care of. I talked to Robert Gober today. I talked to Ellsworth. I should’ve talked to Brice, but I haven’t yet, so I’ll call him this afternoon.

“I will always take an artist’s call if I am on the phone with a collector,” Marks says. “And I will never take a collector’s call if I’m on the phone with an artist.”

“Artists like to think they are the center of attention. And Matthew”—Johns laughs— “is capable of making artists feel that.”

Marks’s clients are quick to return the affection. “Besides being my dealer, Matthew also became a sort of financial adviser to me,” says Marden, who has been represented by Mary Boone and by Pace, and was shown once by Gagosian. “I always needed a dealer who could pay me in advance, and then I paid it back out of future sales. Basically, Mary was just very happy if you owed her money. With Matthew, it is a little bit different. It’s more his goal to get you out of the situation. I could see the light at the end of the tunnel.” And while Marden’s always been fond of Gagosian, he says, “With Larry, I always got the feeling he was most interested in pursuing me. I wasn’t sure how he’d be on the follow-through.”

Such household names as Marden and Kelly had their places secured in the pantheon long before Marks came into their lives, but there are plenty of younger artists whose careers took off when they began working with him. Andreas Gursky’s large-scale photographs, gorgeous though they are, were once considered the stuff of postcards, though in the late nineties he broke records for prices fetched at auction for photography. Nan Goldin was an underground phenomenon before Marks began representing her. “Matthew just allowed her to really get her work together and get it out there,” Marden says. “I didn’t think Nan was being well represented. You can deal with her as an artist or as someone who’s producing product and commodity, and Matthew understood that she was an artist.”

Marks spent hundreds of thousands of dollars (“I’m not even sure how much; I don’t like to think about stuff like this”) on a 2000 installation by a young English artist, Darren Almond, who built “the world’s largest digital clock” out of a 40-foot-long shipping container. Almond photographed the piece as it was transported via barge across the Atlantic into Newark Harbor. Marks funded the project on faith. Almond’s drawings and photographs sell in the range of $7,500 to $15,000, and it will be a long time before Marks earns back his investment on him.