I don't know that much about Columbus, but if you want to head west to Springfield, a), you'll come across 3 big antique malls and off of Rt 72 in Springfield, you'll find the best stores for flannels. They do have other fabrics, but still the best selection in flannels
http://www.creativefires.net/
Depending on where you're at in Columbus, it's less than an hour's drive.