For a massive beach house in South Carolina decorated by Ms. Fischbach, Mr. Wine interviewed the clients at length to gauge their appetites in sports, fiction, politics and religion. He asked Ms. Fischbach about their art — Robert Motherwell, Rothko, Agnes Martin — so he could find monographs on the artists. He researched the area, too, and prescribed a mix of regional histories.

“I think I’m pretty good at extrapolating tastes from a small amount of information,” said Mr. Wine, who created a collection of 4,000 books, packed them up in boxes labeled by room and topic — contemporary mysteries, for example, for the front hall — and sent them off to the house to be unpacked and styled by Ms. Fischbach.

As she put it: “Architects build so many shelves into new construction — it adds warmth and their aesthetic stamp. Thatcher is a necessity at this point in these large homes,” she said, ticking off five projects on which she and Mr. Wine have collaborated. “I couldn’t pull off filling these miles of bookshelves without him.” For his work, Mr. Wine charges from $80 to $350 a foot. The rare vellum is more pricey, at about $750 a foot; the Northern California library he did for the private equity manager cost about $80,000, he said.

In the custom book business, you might call Mr. Wine a designer label and the Strand, ready-to-wear (prices there start at $10 a foot and range up to $400 for antique leather).

The Maryland-based Wonder Book, then, with its 54,000-square-foot warehouse, represents the mass market. Chuck Roberts, its amiable owner, said he gets requests from developers, set designers, decorators needing 1,000 books for a holiday deadline, even wedding planners.

“We’ve had a great year — it’s broken all records,” Mr. Roberts said, noting that his book-by-the-foot business now represents almost 20 percent of his total sales. Though “earth tones” are his bestsellers, he said, last week a national builder asked for light blue and gray books to stage multiple homes. A TV news program wanted linen-wrapped books chopped in half to fit the shallow, faux-shelves of a political interview program. And on Tuesday, a Chicago restaurant called for 100 linear feet of distressed clothbound books. “Must be there by Monday!” Mr. Roberts said.

Federico Uribe, a Colombian conceptual artist working in Miami, is another big customer. He has ordered thousands of books in primary colors to make energetic sculptures of palm trees and boa constrictors. (“Most people destroy trees to make books,” Mr. Uribe said. “I destroy books to make trees. I like that the books are telling a story in a different language.”)