Most of the time from fabric.com, but I've also used jandofabrics.com, and one here locally, fabricdepot.com. Boersma's is another great fabric store. I've never purchased online because it's local, but they have a huge store and a huge selection--another is Greenbaum's Quilted Forest. It's an hour away, but worth the drive. If you do a search, I'm sure you'll find both of those shops.