I can remember seeing this tag on some sheets from Grandmother's closet. I know many older generation people sent out their sheets to be washed at the cleaners because they wanted them white white and ironed. I remember my mother ironing sheets when I was a young child. She oftened did ironing for people. This would have been 60 years ago. I've worked with older seniors who only did their personal laundry, sending all other items to the cleaners, even though they had a washing machine. If those sheets are super nice and appear vintage, they may be worth more in this state than to use in quilting, but they could be used in quilting if you so desire.