I have needed a pincushion for some time. I had the bright idea that I could fill it with silica sand and make it actually a pincushion that sharpens pins and needles while it holds them, so I used the design I found here, lining the fabric with dense, thin quilt batt and filling the cushion with fine silica sand. My thought was the batting would keep the silica sand from sifting through the weave of the cotton fabric and getting everywhere.
As usual, my brilliant plan was not so brilliant. The batt is doing a great job of keeping the silica sand in - about as good a job as it does at keeping sharp pointy things OUT. I mean, like pins. It's so hard to push a pin in to the thing!