Love these!
Someone asked what they're stuffed with and thought I'd share what I use: ground walnut shells, sold in pet stores in the reptile section. It's "cleaner" than sand which can carry mites and not-visible organisms. I like the weight it gives to the pin cushion, preventing it from sliding around the table.
I bought the smallest bag possible - which stuffed several dozen pin cushions I made for a charity bazaar and for the D.A.R. "boutique" at the state conferences. If someone else you know wants to go on a pin cushion sewa-thon, this would be a good item to split the price of. If you go to sewing or quilting expos, some vendors will sell a quart bag of it, but the mark-up is pretty steep for the convenience of a smaller quantity. If you have some left over and know of someone who makes their own soap, crushed walnut shells is a fabulous add-in exfoliant for home made soaps.