What it’s actually like
Step off Main Street into the courtyard at Marshall Square and the tone changes. The big Main Street galleries sell other people’s art; the suites around this courtyard are mostly artists selling their own, and Quan’tum Art in Suite 16 is the liveliest of them. The company belongs to three working artists, John Gleason, Jacque L. Keller and Suzanne Larson, and on a weekday there is a fair chance one of them is in the room making something.
The work is as varied as the owners. Gleason builds contemporary sculpture in copper, metal, stone and glass, and has been working copper since he found a stash of century-old copper roofing foil more than two decades ago. Keller is a juried acrylic painter whose range runs from animal portraits to trompe l’oeil to the frankly imaginative. Larson, who has a background in veterinary medicine, weaves and fuses glass and builds whimsical assemblages of animals doing human things. Gleason and Keller also make pieces together, metal and paint in one work, and those collaborations are what the gallery is best known for. Pottery by Alvin Pace rounds out the room.
The house rule, posted on the door, is to serve everyone and be kind, and the gallery’s own line is that it doesn’t take itself very seriously but is utterly conscientious about the art. Both are accurate.
What to buy
A Gleason-Keller collaboration. Copper and paint in a single piece, the signature of the gallery and the thing you won’t find on any other wall on Main Street.
A copper sculpture. Gleason’s patinated copper, colored with heat, chemicals and acid, from small wall pieces upward.
Glass. Larson’s woven and kiln-formed glass is the colorful entry point and the easiest to carry home.
A commission. Keller paints pets; Gleason fills niches and big walls. Bring measurements and a photo.
Parking, timing and the practical stuff
Marshall Square is the low courtyard complex on the south side of Main Street just west of Marshall Way; walk in from the sidewalk and Suite 16 is among the studios ringing the courtyard. Main Street parking is scarce and short-term. Use the free Civic Center garage off Drinkwater Boulevard, about eight minutes on foot, and the Old Town on foot note for the route through the Old Town core.
The 2026 Arts District guide lists the gallery open Monday, Tuesday, Friday and Saturday from 10 a.m. to 5 p.m., Thursday from 1 to 9 p.m. for the ArtWalk, and Wednesday closed or by appointment. Thursday night brings the crowd into the courtyard; a weekday morning brings the owners’ full attention. The gallery takes Visa, Mastercard and Discover, runs a designer program for the trade, and delivers and installs around the Valley.
Make a circuit of the courtyard while you’re there. King Galleries holds several suites of Pueblo pottery, and Royse Contemporary and Zbavitel Studio & Gallery are a few doors along. Xanadu Gallery is a short walk west on Main.
Eat while you’re there
Sel is across Main Street and is the dinner for an ArtWalk night. Malee’s Thai Bistro has fed the gallery row since 1987, Craft 64 does wood-fired pizza at the west end of the street, and Arcadia Farms Cafe on First Avenue is the daytime lunch.
How it got here
Quan’tum Art began as a partnership rather than a storefront. John Gleason and Jacque L. Keller founded the company in 1998, and by Gleason’s account the two worked out of his home in Chandler for about twenty years before they needed more room. Keller had painted since childhood, studied in the Toledo Museum of Art’s youth program and at the University of Toledo and Arizona State’s art school, and specialized early in animal portraiture and trompe l’oeil. Gleason came to art later, by way of that old copper roofing foil, and never stopped.
Suzanne Larson had shown with the company for years when she joined Gleason and Keller as a partner in 2014. Around the same time the three outgrew the house and took Suite 16 at 7077 East Main, the single-story complex known as Marshall Square. The courtyard was becoming an artists’ enclave in the mid-2010s: Tilt Gallery moved in from Grand Avenue in late 2014, Lotus Contemporary Art arrived from Roosevelt Row in 2016, and Royse Contemporary opened in 2017.
What the courtyard built was a habit of cooperation. In a 2018 Images Arizona profile, Quan’tum, Leslie Sandbulte Art and Blink Gallery described running events together and keeping each other’s doors open over lunch and errands; Keller called it “the best way to run an art business.” The awards followed in the 2020s: Phoenix Home & Garden Readers’ Choice Best Gallery three years running and Phoenix Magazine’s Readers’ Choice in 2025.
Today Quan’tum is one of the anchors of the Main Street Arts District’s artist-run end, a counterweight to the established Western galleries a block east and proof that the district still has room for people who make the work and sell it in the same room.