Katy Messersmith launched an apparel business in one room of her house nine years ago. Soon, it took over the entire house and the garage, so she rented an apartment and moved out. Now the company, Katydid Collection, is in a warehouse near Interstate 35 and Medical District Drive. It did $5 million in sales last year and was listed in Inc. as one of the 500 fastest-growing private companies in America. “I remember when I was shipping 10 packages a day out of my house, and I would think, ‘Gee, if I can just get to 30 packages a day,’ ” she says. “Now we’re shipping over 200 packages a day to small boutiques nationwide.” Messersmith, who lives in Lakewood, has eight full-time employees, and 90 percent of her business is wholesale. Katydid Collection sells some accessories and handbags, plus day dresses and leggings. There are men’s and children’s items, but women’s T-shirts make up the bulk of its offerings. Messersmith designs the clothes and has them made in Los Angeles. She describes them as “comfortable but sexy.” Recently, she added a sportswear line, including baseball, basketball and football-themed shirts. They’ve proven overwhelmingly successful. This past spring, the company sold 5,000 of the bedazzled baseball tees in 24 hours. And that was just the black ones. Now, she offers them to match many school and team colors. She recently signed a deal with the Houston Astros to sell the baseball shirts in Minute Maid Park. “As it turns out, sports teams want to have some things that aren’t licensed,” she says. She’s also working a deal with the Philadelphia Phillies, and her dream is to sell her shirts in Cowboys Stadium and to work a deal with Mark Cuban. Katydid Collection got into online retail in 2002, pretty early, and Messersmith says that’s been an advantage. Her wholesale clients are mostly small boutiques, about 10,000 of them nationwide, in suburbs and small towns. They’re businesses that cannot afford to send buyers to the fashion markets in New York, Atlanta, Dallas or Los Angeles. So they buy online, and turnaround time is fast. Shop owners can receive orders as soon as 24 hours after they click purchase. In much of the fashion world, buyers select clothes a year in advance based on what they see on the runways. But Katydid isn’t a typical fashion business. When a design is successful, it stays on the roster. Katydid has been offering one popular T-shirt design, in short and long sleeves, for more than five years, for example. Messersmith is happy with her niche, and she has no desire to get into upscale department stores. “Give me the cruise ships. Give me the airport gift stores,” she says. “Let Target pick up my sportswear line.” Cavender’s recently started offering Katydid Collection in about 100 of its stores. Another way Messersmith has marketed her business is through charities. She has designed shirts for Susan G. Komen for the Cure, Dress for Success and Kidd’s Kids, among others. “I get to team up with these charities that I love, and they promote me, and I get to give back at the same time,” she says. Messersmith says that along with continuing to increase sales, her goal is to open a flagship Katydid Collection retail store in Dallas in the next few years.