Pam, your handkerchiefs are beautiful! I love the butterfly quilt idea. I have seen one like that somewhere- I think in a library book, but I can't remember which one. If the handkerchiefs were appliqued to a sturdy fabric, they would just basically be an embellishment and not part of the structure of the quilt so it wouldn't matter as much if they are thin. I imagine they would wash well, being designed for nose-blowing! LOL!
And that quilt I posted the link to is probably my all-time favorite quilt of all time EVER! LOL! And the maker gave it away!!! (To her sister- lucky girl!)