Originally Posted by
joe'smom
It was the idea of the sand getting in the quilt (that is, through the bottom weave) that concerned me.
I understand, but my point is that sand is going to be all over the quilt no matter what you do. People with sandy feet will step on the quilt, grinding the sand in. Sand will be in the bathing suits of the people who lie on the quilt. I wouldn't use anything with a loose weave, top or bottom, but be prepared to deal with a little bit of sand sometimes getting in the quilt, mostly through the seams. If the user is particularly concerned about sand getting in from the bottom, they could always throw a drop cloth down under the quilt.