At the intersection of Easthampton’s Union and Cottage Streets, you’ll find One Cottage Street. Look up on the Union Street side, and you’ll see a couple of giant snowflakes in two windows. Those windows look out from the studio space of illustrator and author Ruth Sanderson, who grew up in Monson.

That space is, in some ways, surprisingly sparse. The spot just inside the windows holds her easel, and on the day of our conversation it bears a large canvas that Sanderson says she’s been working on off and on for a long time, a scene with a jewel-winged fairy sitting on a rock in a pool, gesturing toward a unicorn. A cloud of butterflies winds toward the unicorn.

The sparseness doesn’t translate to the walls—there you’ll find a large number of paintings, from quite small to imposing. Some also hold fairies, but the subject matter includes landscapes, gnarled trees, and even a dark knight on horseback who looks ready to gallop right over the viewer.

There are commonalities—most of the paintings seem to hail from the world of fairytale, an inexactly defined period with medieval trappings like castles, antiquated dress and, when you look closely, fairies, elves and all manner of small enchanted creatures peering out.

There’s a stylistic bent, in a fair number of pieces, toward the Renaissance. “You can’t beat the 15th century,” Sanderson says with a smile.

She opens one of her books, and what lies within is more illuminated manuscript than standard-issue kids’ book. It calls to mind the stunning early 15th-century Tres Riches Heures du Duc de Berry, an illustrated calendar that straddles older and newer stylistic elements of that age with awkward (to modern eyes) perspective, sharply rendered castles and rich, luminous blues.

One of her works on the wall was commissioned to look like a landscape by a Dutch master, and that’s exactly what is appears to be, down to the singular brushstrokes that make up the limbs of trees. Another offers a precise, nearly hypnotic rendering of surface details (like folds of heavily jewelled cloth) that would seem right at home on the canvas of a northern Renaissance master like Jan van Eyck.

It seems remarkable that Sanderson, who tells me her bibliography numbers 80 books, can not only borrow so gracefully from masterful styles past, but do so at the pace necessary for a career in illustration. When she was a young student, Sanderson says, she tried to reproduce the well-known Edouard Manet painting “A Bar at the Folies-Bergère,” a canvas from the 19th century.

Says Sanderson, “I kind of nailed it! It made me think, ‘Hey, maybe I could be an art forger.'”

Illustration, despite its sometimes second-class status relative to the “fine art” world, is a technically demanding discipline that rewards just such chameleonic abilities. The more time you spend looking at her work, the more you realize that Sanderson is an exceptionally gifted artist. She decided early on that the fine art world, with its then-increasing emphasis on concept over craftsmanship, was not for her.

“I wanted to be a representational artist,” Sanderson says. “It was the late ’70s, and I was lucky to be in on the illustrated book boom. I was in the right place at the right time.”

That bit of serendipity soon saw her illustrating Nancy Drew paperbacks, and nearly 40 years later, her substantial catalogue includes titles she’s also written, and one written by her daughter, Whitney Sanderson.

Right now, Sanderson is finishing up a new project, A Castleful of Cats. “I’ve been working on getting the rhyme exactly right for years,” she says. She’s also seen a rebirth of a title from 20 years ago, The Twelve Dancing Princesses.

Though her concerns often seem old-school for the ever-snappier and fast-moving world of kids’ books—her many works include lots of retold fairy tales, books of saints and other religious subjects—Sanderson seems to be adjusting to the new realities of technology that have authors and artists of many a stripe concerned for the future of the medium. In 2011, Sanderson’s Cinderella came out as an iPad app, a good example of her contention: “There will always be stories, no matter the medium.”

All the same, Sanderson says, she’s not quite gone the way of some illustrators who create their works entirely digitally. Her studio’s simplicity reflects the methods she employs—her canvases are often large, and the sheen of oil paint with which she fills them can’t be created digitally.

The market for kids’ books, she says, is getting tighter. That’s fueled in part by the rapid turnover of new book lists. “A lot of people only order from the new book lists,” she says. That leaves reprints and even fairly recent titles out in the cold unless they’ve sold exceptionally well. Sanderson clearly has a substantial presence in the market, especially with her long track record.

Still, she says, “I’m just happy to be publishing any books. To put one book in one child’s hand, to touch a few children, is important and rewarding.”

Check out Sanderson’s art, books and Easthampton Bearfest bear May 19-20 at Studio 307, One Cottage Street, Union and Cottage Streets, Easthampton. Sanderson is painting her bear at the Manhan Cafe, 72 Union St. through May 18.