I did make a mistake and from the ad pictures, thought it might run small so I went a size up to medium instead of small. Definitely should not have. It is true to size.. so medium is a little large with a slightly longer skirt than a small would have been so I wi probably have this taken in a little. The material is polyester but similar to name brand type polyester outfits. I tried black only because it was different and white in the pictures seemed a bit too obvious. But now I think I would've like white also.In any case, it is actually nicer looking on and I could use it as a romp type dress in the summer for other sports or as a cover to the beach too. The dress has pockets as well as the separately included pants, so it is great for tennis playing.. all will hold extra balls for use. It moves well. Material might become a little hot regardless of color.. is ok if needing to sweat a bit (like some extreme running workout gear meant for sweating) so I know it is an early morning or fall tennis type use for me. Overall very stylish, nice.. and excellent if you belong to a club and want to hang, lol