Smartwool Merino 150 Long Sleeve Base Layer You might know Smartwool best for its socks, but this Smartwool Merino 150 Long Sleeve Base Layer ($85) will quickly become one of your go-to tops. The shirt's nylon core will ensure it lasts, too. Image Source: smartwool.com Smartwool Merino 150 Long Sleeve Base Layer $85 from smartwool.com Buy Now