ST. PETERSBURGIn an alley tucked between high-rise condos and an office park in downtown St. Petersburg, Jeffrey Sincich works quietly despite the incessant humming of the air-conditioning unit just above his head. If it weren't for the 10- by 20-foot vibrant mural beside him, Sincich would probably go unnoticed. Wearing a blue flannel shirt, straight-legged khakis and canvas blue sneakers, the fledgling artist, at 23, blends in with the youth that stroll along Central Avenue.As Sincich hoists himself up on a ladder and pencils in where his paintbrush will follow, curious passers-by stop and stare. Some call out questions through the metal gate he works diligently behind.He explains that this mural is the latest work of J&S Signs, a business he formed with Josh Stover, his University of Florida classmate. While Stover, 26, is away at an art residency in West Palm Beach, Sincich puts the final touches on their first fully commissioned wall mural, "Grow With Your City," on the side of the Lemon Grass restaurant."That's why we like public art," Sincich said. "It's relatable, and anyone can interact with it. It's not just people who go to galleries."• • •Neglected outside walls, overlooked convenience stores and inconspicuous street corners are where Sincich and Stover find their canvases.The pair are the latest artists to cash in on the wall mural craze that has been a byproduct of revitalized urban areas like Miami's Wynwood Art District. In the past 10 years, murals have surfaced in downtown St. Petersburg, more commonly around the 600 block of Central Avenue.The city of St. Petersburg is amicable about murals, said Elizabeth Brincklow, manager of the city's office of cultural affairs. As long as the property owner and the artist have an agreement, murals are free-for-all."Murals really create a placemaking similar to public art," she said. "It's a wonderful turning point for us and the city."But instead of busy graffiti art, Sincich and Stover share a common interest in typography, 1950s-era signage and positive mantras.In fact, their friendship was formed from those common interests as ceramics majors in their junior year at UF. But their similarities extend beyond artistic interests. Both men are Pinellas County natives: Sincich graduated from Largo High School and Stover from Boca Ciega. Both men share the same initials, hence their business name, J&S Signs."We just became good friends and influenced each other and gave each other good ideas in the studio," Stover said.Sincich conceived the idea of painting murals after his eye caught an existing mural of shutters and birds on the north wall of Discount Food Mart at 2157 Central Ave."There was already something there that I could add to it," he said. "I thought it'd be easy for them to say yes."Sincich took a photo of the building, then sketched a mural by hand on paper. He scanned that sketch into his computer and used Photoshop to impose the design on the building. The mart's owner, Mike Mekhail, was impressed. His mural simply added "Meet Your Neighbors" in a Western font.While riding his touring bike, Sincich spotted another contender: the Stop & Shop at 432 First St. N. In old Florida pastels, Stover and Sincich painted "Pay It Forward."Customers take it to heart, manager Sam Farhat said. One day a man came into the store, he said, gave him $50 and told him to pay it forward. About 10 minutes later, two homeless men came in hungry. Farhat gave them both sandwiches."It actually became a good thing," Farhat said. "People notice it."Sincich and Stover were asked to do a smaller mural on the side of the Morean Arts Center at 719 Central Ave. This one featured "You are My Sunshine."From there, J&S Signs took off. The pair would email ideas back and forth to each other for upcoming wall murals. Stover would drive from West Palm Beach just to paint.Depending on size, location and design, murals cost upward of $1,500.Though Stover is at his residency and Sincich works part-time at the admissions counter at the Museum of Fine Arts, both men hope to turn J&S Signs into a full-time venture. They've already signed on to paint a mural for an upcoming bike shop on Central Avenue.When Osprey Management, which manages the building where the Lemon Grass is, was awarded a beautification grant for a community garden, they wanted to include a mural. Osprey turned to artist Michele Tuegel, who owns a gallery in the same building, for a reference."Right away, I thought of Jeffrey and Josh," Tuegel said. She's familiar with their work; she features Stover's pottery in her gallery and employed Sincich for a few months.Every now and then, Tuegel would walk down the street to check up on her proteges' progress."Somehow the world made them come together," she said. "It's kind of like twins separated at birth."• • •His blue eyes peered through his vintage tortoise glasses, examining his work. Sincich dipped his skinny brush into a plastic Starbucks cup filled with hunter green latex paint and traced the veins of the milkweed leaves, adding dimension to the mural.He portrayed plants to be grown in the garden. The lime green leaves frame the mural's theme, Grow With Your City, painted in stocky, blood-red capital letters shadowed also with lime green. Lantanas blossomed in sky blue. Spiderwort flowers boasted a bright orange. The three colors were blocked like the palette of a Wes Anderson film.As Sincich cleaned off the chalk marks on the stucco wall, Mike Boriboun took a cigarette break from his shift as a sushi chef at the Lemon Grass.He has watched the mural come alive over the past two weeks."Even though it's city life, you still get nice artwork," Boriboun, 20, said.Colleen Wright can be reached at [email protected] or (727) 893-8913. Follow @Colleen_Wright on Twitter.