Transcript for David and Goliath Fight Over T-Shirt Design
We turn now to a David and goliath showdown tonight. The stay at home mom and those two t-shirts. The one she's wearing, that's her invention, and the one she's holding, being sold at target. Tonight, that mom speaking out right here, saying it's no coincidence. Here's ABC's Neal Karlinsky. Reporter: Imitation may be the sincerest form of flattery, but Melissa lay says retail giant target flat out stole her best-selling design. Total shock. It was all surreal seeing it there in a store I shop at. Reporter: The stay at home mom started this t-shirt business out of her Oregon garage last year. You work so hard on these designs. I screen print until my body ache is. Reporter: Which is why she couldn't believe it when friends started sending her photos. Here's my design. Reporter: A shirt she says is almost identical to hers, being sold by target. It different take us long to find it. Here it is at this target store. Listed for $12.99. That's half as much as Melissa is selling it for. We've followed these kinds of fights before. Dan brown, inventor of the bionic wrench, who told David that sears copied his tool with a version made in China. What did you think when you saw it? It's a knockoff. No question. Reporter: Sears says they didn't steal anything. And tonight, target has sent Melissa this note, saying they "Take the matter seriously and have begun an investigation." Melissa says her t-shirt battle is David versus goliath, and she's counting on target to do the right thing. Neil Karlinsky, ABC news, Seattle.
This transcript has been automatically generated and may not be 100% accurate.