cotton poplin
 

i know this is a little thicker but was wondering if anyone has mixed it with quilting cotton in a quilt .I was told i could wash to make it softer.
thanks for any opinion Gale

Oh yeah. Poplin is a common shirting material, and people make quilts out of dress shirts all the time.

Most clothing fabric is going to be ok to put with quilting cottons if it's not stretchy. People just don't wear a lot of fabrics heavier than denim outside of protective gear, and the stuff that's too light, like organza, is pretty obvious. The one caveat is if you're doing really small, fine piecing, any difference in fabric weight, texture, or thickness is going to make that more of a challenge.