Artist Gwyneth Leech likes coffee, and the usual delivery system for the New Yorker is a paper cup. A couple of years ago, cup and art collided. During a get-together with other artists, Leech spontaneously grabbed her paper cup and began to draw. “I drew in order to stay focused in a room of creative people and ideas,” she explains. But she became intrigued by the interplay of form and image, the continuous nature of the markings as they traveled around the vessel. “I realized the surface lent itself to drawings.”

Buying a beverage is a daily event for Leech, 55, and the drawings soon became daily, too (although “sometimes I save up and work in batches,” she admits). Her favorite tool is a brush-tip Faber-Castell Pitt pen, using high-quality India ink. She also uses black sumi ink, a variety of white ink, watercolors, acrylics, and oils. Her drawings depict everyday scenes (buildings, plants, vehicles, even coffee cups), but also abstract, intricate patterns. The imagery has a snapshot-like quality – well-matched to the impermanent paper surface.

In 2010, Leech began to document her cup drawings on a blog, Gwyneth’s Full Brew. Add Instagram, Twitter, Facebook – interest spread. And soon enough, Leech married her cups with her long-standing interest in public art.

Leech first set up in a window of an empty storefront in Manhattan’s Garment District, a public art space sponsored by what is now the Garment District Alliance. Equipped with cups and drawing materials, she waited to see what would happen. “My window was on a side street, and what was initially interesting was the way people didn’t notice me there,” she says. “And then there’d be a moment when they did.”

Her next stay was in the city’s Flatiron Prow Artspace, which is cosponsored by telecom company Sprint. In Leech’s case, they also sponsored a three-month residency where people could come inside to draw alongside Leech and take their creations home with them.

“People in the window became part of the experience,” she says. “The sense of inside and outside had all this interesting interplay.”

Thanks to Leech’s popularity with the public, her residency was extended to five months. “I worked for four hours a day there, five days a week,” she says. “It became arduous.” But an upside of her prolonged presence was the chance to become part of people’s routines. “One preschooler and her mother made a ritual of stopping by every afternoon,” she says. “I loved how I became part of their lives and they of mine. The girl’s perception of art grew through our daily connection.”

To make art in public spaces and welcome passersby into the process is a powerful catalyst, Leech believes. “People see that an artist can make work anywhere, and make creative spaces anywhere,” she asserts. “That all you need is a pen and a cup, something so mobile and compact – to have the chance to experience this firsthand demystifies art.”

In 2012, Leech’s cups caught the attention of retail company Anthropologie, which manufactured stoneware versions of her paper designs. When the product launched last year, the company flew Leech to London during the city’s Design Festival to create a dazzling installation at its store on Regent Street, accompanied by a five-day opportunity to make art in the storefront window. Back in the United States, Leech also set up at the retailer’s Brattle Street store in Cambridge, Massachusetts.

To date, Leech and her cups have also exhibited in Scotland, as well as Texas and New Jersey; she has packed them up and taken them with her on trips to Florida, Mexico, and Ecuador. And more than 1,000 cups later, Leech recently began exploring a new venue for her project. It’s exactly where you’d think she might have started: coffee bars.

Sarah Werthan Buttenwieser is a writer based in Northampton, Massachusetts.