rb Miramar for the whole family. Introducing Mini rb Miramar, a new collection of kids' clothing featuring our revolutionary printing technique that makes any material resemble denim. This children's long-sleeve T-shirt is made from breathable cotton that's soft on the inside and printed on the outside to look like a denim top. With the seams and other details digitally rendered on the fabric, your little one will love its ultra-comfortable fit and feel (just as you'll love that it's machine washable).