Thanks everyone for your replies, really appreciate it. The instructions for my cotton batting advise not to machine wash it first. It says you can hand wash it but "if pre- washing batting is not desired we recommend that directly after completing your quilt....should be machine washed ....this will give your quilt the perfect antique -wrinkled look". I've got into a habit of prewashing fabric as once I had some fabric that seemed to shrink on ironing, which prevented my pieces lining up.
On another matter, just in case I don't use this cotton wadding on this project - i've heard that cotton wadding is necessary for baby quilts - is this true?
Thanks again everyone & happy quilting 😀
xx