I do use men's shirts in some of my quilts, especially if I find a color that I can't live without. Being in Florida the thrift stores have a lot of tropical print shirts. Many of these are wonderful cotton fabrics and splendid colors. Just beware of the poly/cotton mixes and rayon and silk/rayon mixes in the tropical patterns. Near us is a thrift store that has them for $1 sometimes and I try to buy then. Only problem I've found is that you're limited in the size of fabric pieces you get from them.