There are no more than two hours of sunlight left on a Tuesday in April in Denver’s Elyria Swansea neighborhood. As the A-line carries passengers past the 38th & Blake Station away from downtown Denver, local street artist Casey Kawaguchi is perched on a ladder, hard at work. His hands and wrists are covered in paint, and a respiratory mask covers his mouth and nose. He’s in the process of giving a warehouse door a much-needed makeover.

In the nearly three hours that he’s been there, Kawaguchi has transformed a blank warehouse door into a sharp, black-and-white visage. It’s a work in progress, but soon, the finished product will become another familiar face to A-Line passengers on their daily commute. (Click through the slideshow below to see Kawaguchi working, as well as the completed mural.)

Kawaguchi, along with an ever-growing community of Denver’s street artists and muralists, are bringing new life to neighborhoods all over the Mile High City. Stroll through RiNo, Baker, Lincoln Park, or Capitol Hill and you might just leave with the impression that everyone in this town carries a spray paint can or paintbrush in their back pocket.

The art typically comes to fruition because an artist has contacted a business or property owner to get permission to re-envision a wall, or because a business or organization commissions a piece from one or more artists. These works might be replaced in a few months’ time by another piece of art.

One such curator is RiNo-based Creative Rituals Under Social Harmony (CRUSH). In fact, CRUSH is the organization that invited Kawaguchi, along with a few other artists, to brighten up the warehouse walls down the road from the 38th and Blake Station.

Once he gets a new gig, Kawaguchi gets to work as soon as possible. When we found him working on the piece on Blake Street, he didn’t have much in the way of equipment. Aside from the ladder, Kawaguchi had nearly a dozen spray paint cans, a paintbrush, some paint, and a water bottle—all of which fit into his reusable grocery bag.

Kawaguchi freehands all his work, which is worth noting to some in Denver’s street art community.

Gamma, a street artist who prefers we use his nom de guerre, has been working in Denver for 10 years. He’s a staunch defender that real street art is improvised, done by hand, and finished in one sitting. He believes those qualities separate street art from mural art—even though some people use the terms interchangeably. Artists who use a projector, he says, disrespect street art’s tradition. “The whole point of street art is that it’s done on the fly,” Gamma says. “But the trend now, because it’s easier and faster, is to project the art and then trace it.”

Most passersby won’t know the difference, and not all artists feel as strongly about this as Gamma does. “There is the opinion out there that using a projector is cheating,” Kawaguchi says. “But I don’t care whether an artist uses a projector or not. To each their own.”

As the day comes to a close, Kawaguchi adds black bangs and hair, which fill the remainder of the frame. Final details such as symmetrical beauty marks, eyelashes, and his signature provide the finishing touch. He posts a shot to Instagram, titles the work “Bae Door,” and leaves it for the masses.

“I love not only that it’s public, but that with street art you can randomly walk up on a mural,” he says. “There’s something special about the impact of unexpected art.”

Curious to see more street art from the artists featured in this article? Follow these artists on Instagram.