I too am of the opinion that the 100% cotton cloth available on the bolt at the fabric stores is the better choice. Square patches, round patches or cut at the muzzle patches all perform very well. I prefer the 100% cotton drill cloth from the utility cloth section of JoAnn's Fabrics, but their offerings from pillow ticking through canvas are very good. Just be sure to verify that the fabric is 100% cotton or 100% linen from flax. You can take a micrometer to the store to check the thickness of the fabric. Before using the fabric as a ball patch, wash in hot water to remove the starchy sizing that doesn't let the lubricant soak into the weave.