I like to stick to natural fibers for baby quilts for two reasons, breath-ability and exposing the infant to less chemicals. Poly batting, while I love it for most quilts is made of chemicals and why expose little lungs to anything more than necessary. Fine once they are toddlers. Also, young infants can't easily kick off the covers if they get overheated so I like to stick with a fiber that will breath and avoid that if possible.