Delicate magnolia branches dance around a doorway in the sprightly hall mural of an Alexandria home. Beckoning through the open passageway, an elegant, faux-painted table repeats the palest gray-blue of the mural’s leaves and flowers. In the dining room, fabric on slipcovered chairs is embellished with a monogram combining the husband and wife’s initials.

Painting decoratively to resemble whatever is in the hearts and minds of homeowners and their designers is all in a day’s—or several weeks’—work for the talented team of Billet Collins. Painter-in-chief Barbara Billet first called on her oldest daughter, Kellie Collins Hodges, for help 25 years ago. Amy Collins Matthews, the youngest of the three daughters, joined them a decade later. Together, the trio has custom-painted floors, walls, ceilings, furniture, fabrics and many other surfaces. When the pace is brisk, their core team expands to a handful of longstanding associates including Roberta Marovelli, who hand-painted the magnolia mural in the Alexandria home.

Billet Collins’ style spans the design spectrum. “We’ve done graffiti art and we’ve done Greek-key patterns,” says Hodges, seated with her colleagues/family members in the living room of the house in Darnestown, Maryland, where their studio is based and where the sisters grew up. Over the years, the focus of their art has remained constant.

“We care a lot about what the designer and homeowner are saying and about achieving what they want to see,” Billet observes.

One of those designers, Wendy Danziger, recently asked Billet Collins to create a ceiling mural for a 300-year-old stone house in Chadds Ford, Pennsylvania, based on an antique map. It required nine months of iterations, during which the artists prepared custom samples following each change. Eventually, the expansive 20-by-11-foot mural was charmingly hand-painted on canvas in Billet Collins’ studio and delivered to the site.

Although their work focuses on residential projects, the artists have also brought their expertise to historic properties. When they were asked to apply a historically accurate, fantasy faux-bois treatment to the doors and trim at President Lincoln’s Cottage in Washington a decade ago, Hodges had just completed a course with British marbling and wood-graining master Bill Holgate. The team got it right and has since returned to do touch-ups.

Billet met another challenge at DC’s Decatur House when called in to paint newly installed floorboards to blend in with existing originals. “It had to look exactly the same in color and match the signatures of the artists from 200 years ago,” Hodges notes.

Billet Collins’ own signature draws on far-ranging genres to achieve a fresh, tailored, contemporary look, which suits the Washington region’s prevailing style, described by Billet as “Southern tradition pushed by New York contemporary.” She gained an early appreciation for art, influenced by her father, William Billet, an artist who worked under cover for the CIA and later headed the agency’s graphic-arts reproduction branch. She went on to pursue fine art in Frankfurt, at Indiana University and at the Corcoran.

Her daughters arrived in the business via other routes. Matthews, who also studied art in college, now creates abstract paintings for Billet Collins’ clients and for sale online. Hodges, who has a degree in Russian Studies, was working as a barista on the West Coast when her mother asked for help on a big job in Chicago. Among many tasks, Hodges had to paint a motif across a large floor. “The owner was a famous mathematician, so the layout was kind of important,” Hodges recalls.

“I love math. And I love pattern,” adds Billet, who with her polished techniques and unassuming manner proves that art and math abilities can coexist. When laying out a pattern, she explains, exact measurements are paramount. “Three-quarters of an inch matters. You can’t get to one end and have an element that’s larger.” That sleight of hand takes place in the loft studio above her former garage, where stenciling on two floor cloths is currently underway. To create the illusion of perfect symmetry, the pattern motifs were stretched a quarter inch at a time before any stencils were cut.

That same attention to detail is evident in the spacious, well-ordered studio below. A set of dark chairs awaits lightening glazes, while a brassy metal mirror frame is becoming more muted. “After years of working with the paints, you get to know exactly what the colors will do,” says Billet.

The team always enjoys a fresh challenge. In the house, samples of their designs are displayed on fabric, paper and porcelain. They surmounted a steep learning curve to produce limited-edition place settings in a cheerful pattern of Ottoman curves and clean, contemporary geometry. The line came about after Nadia Subaran of Aidan Design asked if they had any hand-painted porcelain. “Yes, we do,” Hodges recalls replying, and waits a beat before she adds, “That’s our answer for everything.”

Billet Collins’ services are available through designers; their products can be purchased at billetcollins.com.