When was the last time you washed your makeup brushes? Don't answer that. We know it's probably high time you get some spiffy new ones, and Sigma Beauty's flagship boutique at the Mall of America is a good place to start your search. Sigma Beauty was initially founded as an online store in 2009. Since then, the Minnesota-born company has garnered international fans for its innovative brushes and makeup. Most of Sigma Beauty's brushes are made with the company's own exclusive synthetic fibers that hold up to even the most vigorous makeup application, and they're hypoallergenic for folks who don't want to use animal hair on their faces. (And they're ultra soft, too.) All of Sigma's stuff is affordable, which is good because you'll want to buy just about everything.