I had a wonderful dress out of poly/cotton gingham (made it when I was in high school) and Grandmother cross stitched around the hem and the sleeves. I also have some great aprons she made -- all bright and cheery. My other grandmother made me several kids dresses when I was little -- and later she put the scraps into a quilt with scraps from other clothes she made me -- it held up great and teh mixture of fabrics is not an issue. If I mixed cotton and non-cotton I would shrink the cotton.