Like others I have tried old blankets, shirts, etc. In the past military surplus patches were the rage but I never liked because they didn't like to absorb water. For years now I make my own from baby blanket flannel bought at Wal-Mart. Color not important. If some is on sale that is what I get. I have an antique pair of tailor scissors that I use to cut into (aproximately) 2" squares. Size not critical. Just use a proper jag with a rebate.