JANESVILLE — At the end of his junior year in high school, Jamin Arn knew exactly what he wanted to do, and it didn't involve his senior year and the two credits needed for a traditional high school graduation.

"I wanted to get out and get moving," said Arn, who as a 17-year-old left Kentucky and moved to Janesville to live with his grandparents.

A night course satisfied the two-credit conundrum. A job at Hardees confirmed for Arn that he what he really wanted was a business of his own.

Several entrepreneurial efforts later, Arn owns the Janesville-based OfficePro, a supplier of office products and furniture and commercial janitorial supplies.

Founded in 2003 in his basement, OfficePro closed 2007 with three-year revenue growth of 409 percent, good enough to land the company in the 883rd slot on Inc. magazine's list of the 5,000 fastest growing privately held companies in the United States.

With several addresses behind it, including one at the former Parker Pen building, OfficePro is now at home in a 35,000-square-foot building at 615 N. Parker Drive, just south of Traxler Park. Arn's formation of OfficePro followed sales jobs with three other office supply companies, including Wagner's in Janesville and Beloit.

Rows of desks, chairs, tables and cubicle equipment are surrounded by reams of copier paper and other office odds and ends.

"It's not pretty, but it's not supposed to be," said the 31-year-old Arn.

A flashy showroom would only add to the company's overhead, a cost that would ultimately be paid by OfficePro's customers who range from Rockford to Wisconsin Dells and Delavan to Monroe.

OfficePro is primarily a non-stocking supplier, meaning the company doesn't carry 98 percent of what's in its 30,000-item catalog. But Arn said the company's hallmark is service, and any one of those items can be in a customer's office within a day or two.

Arn said OfficePro and its 13 full-time employees are probably four or five years away from a new building. In the meantime, he's content to focus on growing the company that so far has matured beyond his wildest dreams.

In 2006, OfficePro bought the Janesville-based Warmke Office Equipment. It later bought Used But Nice Office Furniture in Madison, and Arn said he's considering another acquisition.

The company, which recently added a shredding division, is boosting its bottom line with acquisitions and internal growth, he said.

"You need both to grow," Arn said. "When you're generating internal growth, you're likely expanding into someone else's territory.

"You can buy growth, sell deeper to your existing accounts or cold call, but that taxes your sales force to some extent."

Arn loves the cold call, something he wishes he had time for every day. It's that willingness to put himself in front of potential customers that's helped him succeed in business, whether it's been the Cutting Edge Lawn Service, Big 10 Subs or property rental businesses he's owned.

"I honestly thought lawn care would be my supreme biz because I loved being outside, mowing and being able to look over my shoulder at a job well done," he said. "I thought that in the supply business I could just establish a solid customer base and then collect the residual income."

But then Arn met Ken Hendricks, the founder and CEO of ABC Supply, a company to which Arn was already selling office products.

The two came from similar backgrounds and they shared a passion for entrepreneurial success in a variety of businesses.

"Ken would always challenge me, ask me, ‘What if this, what if that,'" Arn said of Hendricks, who died in 2007. "With OfficePro, I wanted to do it better than Staples or Office Depot and with ABC, Ken wanted to do it better than his competition.

"I just tried to suck as much knowledge out of him as I could."

But Arn is quick to say any parallels with Hendricks end there.

"I'm no Ken Hendricks," he said. "I'm just a young buck trying to make a living."