one of the quilts in the book of 100 top quilts in the past 100 years is a quilt made all by hand using silk clothing labels...it is an awesome quilt! using the labels would only be a problem if you made a pair of pants then took a levi label off a pair of jeans and put it on the pants you made... that would be a big no-no. but leaving the labels on the clothing you are using should be just fine.