My opinion is that if the baby quilt will be USED, the fabric should be 100% cotton. If it will be a wall hanging or just "for show" then use whatever fabrics you care to use. When I make little baby quilts I don't make the "Heirloom" variety. I tell the new mom that this little quilt can be thrown in the washer and the dryer. The baby can play, pee, poo, and puke on it and it can be cleaned up and used again. Cottons are so much more comfortable, too.