Shark Tank

Here's what really surprised the co-founders of Thompson Tee on 'Shark Tank'

We're all subject to the occasional fashion faux pas, yet nothing quite compares to the obvious sweat stain. Two friends, Billy Thompson and Randy Choi, were no strangers to the dilemma. With a lack of antisweat apparel on the market, Thompson and Choi set out to create Thompson Tee — a clothing brand built on sweatproof technology and ultrasoft material.

"At Thompson Tee Inc. we invented and patented an undershirt that is guaranteed to block underarm sweat, preventing those embarrassing sweat marks and yellow stains," Billy Thompson said in an email to CNBC. "Necessity was the mother of invention; both Randy and I have dealt with hyperhidrosis (excessive sweat) since puberty."

In order to gain capital to bring production in-house, Thompson and Choi went on "Shark Tank," seeking $700,000 in exchange for 7 percent of the business. The sharks were impressed with the product's functionality, but the $10 million valuation had them scratching their heads.

"Who's paying more than 10 times for T-shirts?" Kevin O'Leary asked.

"Patented T-shirts," Thompson corrected.

Mark Cuban chimed in with, "The technology — quote, unquote — is fine. It serves the purpose, but you're really a marketing company."

Being labeled as a "marketing" company wasn't exactly the response the two inventors of antisweat apparel were expecting. Looking back, Thompson said, "Of all the objections that I thought we'd get, I never thought we'd get that one."

The marketing label wasn't the only thing that surprised the entrepreneurs. According to Choi, Daymond John's response was also shocking. Despite the investor's experience in the clothing industry, he said he didn't want to be in the inventory business.

"We were stumped. No inventory?" Choi said. "OK, that leaves software and services business — clearly not our business."

In terms of their behind-the-scenes experience, the entrepreneurs were delighted to meet the other guests of the show.

"I actually met an Olympic bronze medalist — she was part of the pitch for one of the entrepreneurs. She let me put her medal around my neck, something I've never had the privilege of doing before," Thompson said. "Check that off the bucket list."

Thompson said their company is doing great today, having been able to maintain and grow from the momentum "Shark Tank" provided. Post-airing, the entrepreneurs received a surge of calls and emails, which Choi described as "kind of overwhelming" in the midst of running the business. Sales, exposure and expansion have all been part of the journey post-"Shark Tank."

To conclude, Choi had one last piece of information he wanted viewers to know about his time on the show:

"The TV does add 10 pounds!"

Don't miss the antisweat stain team pitch Thompson Tee on "Shark Tank" Sunday at 10PM ET on CNBC.