Thank you all for your advice. As I said, these sheets are old, some with small holes. They are not good enough to be used as a quilt back. I was concerned if it would quilt up differently than muslin for practice FMG. Holice's suggestion of a different needle was something I had not thought of. I suppose I may have to try out different types of thread too if I run into proplems. Maybe I will only cut-up one sheet today and see how it goes.