By all means wash it first. I bought some one time and when I washed & dried it , it was a wadded up mess. It was so hard to iron that I decided not to use it except for non washing projects. There are many different grades of muslin on the market so be choosy. I think what I got was almost homespun. It was ruff like too. So before you put it on a very nice top be sure what you are getting.