“Young guys who don’t know any better,” Jerry Kozak says, shaking his head and grinning.

In 2008 Jerry Kozak and longtime friend Ricky Winowiecki, both ­twenty-two, opened the Ann Arbor T-shirt Company in their apartment. Last year, they moved into a 32,000-square-foot warehouse on S. Maple and expect to close the books on sales of 750,000 T-shirts to customers around the world.

Theirs is a literal rags-to-riches story.

As an undergrad in the business school, Kozak had printed T-shirts on a “hobby-grade” press in his dorm room at Mary Markley Hall, earning “a couple of hundred dollars a month for college.” (Winowiecki, a computer engineering major, did the website and computer graphics.) With a $16,000 investment from “family, friends, and former employers,” they moved the press into an apartment on Fuller St. then into a 1,000-square-foot warehouse on the corner of South Industrial and Jewett.

“We built bunk beds there because we couldn’t afford both an apartment and a business location,” Kozak says. “I have to say: that was demoralizing. I’d spend eight hours a day selling our merchandise, then ten hours printing, and then go around the corner from the press to crash in a La-Z-Boy.”

They initially relied on Facebook for sales connections. “In the early days of Facebook, groups would cluster around pop culture interests—’I love kiteboarding,’ for instance—and we’d message the owner, offering a free kiteboarding shirt if he would send our link to the entire group. It was a great way to reach a thousand people at once.” But within months, Facebook limited the reach of unpaid posts—and the men’s business plan dried up.

“We probably wouldn’t have succeeded if we’d started our company six months later,” Kozak suggests. “We made every mistake in the book. Ricky and I have authenticity. We started from the ground up, and we’ve done every job, so we know what we’re asking our employees to do.”

After several tough years, the partners got a break: massive orders from the ­U-M-based A Very Potter Musical. “When the musical became an instant hit, we had our first tiger by the tail,” Kozac says as he begins a tour of the building, where installers are putting solar panels on the roof. “Instantly, we had to learn about international shipping and ordering. We treated that income as an investment, to build our product offerings on Amazon.”

Seventy percent of their sales are generated on Amazon, which advertises their thousands of designs, stores 300,000 shirts in Amazon warehouses, and handles the logistics. They now have fifty full-time employees, plus as many as thirty seasonals during the frenetic holiday season.

“Our new place is definitely a work in progress,” Kozak says, greeting Heidi, one of seven dogs that come to work with their owners. “We liked the old industrial features of the building, and we like being part of a neighborhood. We want people to drop by.”

The front door on Maple opens onto the sales department. A few North Face and Patagonia shirts and jackets hang on the wall, hinting at plans for a showroom. Temporary walls section off the different departments: designers, shippers, embroiderers, one small conference room, and a kitchen area with long banquet tables. Every day the owners buy lunch for everyone.

“Our first press was abysmal, a nightmare,” Kozak says as he walks into the massive press room. “We learned quickly that you can either save money temporarily and pay later or buy the best. We now buy the best.”

He recalls the time when the company mismanaged an early order. The partners worked through the night to correct the problem, then delivered the new shirts with a cake that read, “Sorry we suck.” Kozak grins. “The lady laughed so hard. But she kept sending us orders. We knew we had to crawl out from under mistakes and make things right.”

As he watches shirts being printed, folded, packaged, and packed, he adds, “We have a big, audacious goal: to make our own apparel”—with machines doing the stitching. Robots haven’t made many inroads in the apparel industry, he explains, because fabrics stretch and easily stain. But he is optimistic that the hurdles will be overcome.

“We’d love to be the first—or one of the first—to bring the technology to Michigan and make apparel here,” he says. “We’re saving up for the time when viable models will be ready. That’s my dream.”