I use PUL for some beach quilts and other times I use an older quilt that is still in good shape but also works for the beach. I have not had any problems with sand getting inside the quilt. I used a lighter weight poly bat on the ones I am talking about. PUL is easy to work with and is water resistant. I use it for bibs and burp cloths too. (Polyurethane Laminate Fabric). I also have the PUL over a cloth backing.