The 10 ounce, 12 and 14 denim I have been using for years still works fine for me, as patching material.
Over the last couple years, I've been using the newer 10 ounce that I measure at .021" heavily compressed in calipers.
It's been working very well. It also compresses .0015" more than the 10 ounce denim I bought 6 or more years ago, so
the mfg'r is different than prior.
Although it compresses more, it still seems to work very well in my .36, .50, 20 bore and .69. I saw, at a Joanne's store in
Yuma, Ar. some years back, 11 ounce denim. That would be about perfect, imho and wish the stores here had it. They don't.
I also used this 10 ounce denim with bore sized balls in the .36, my now gone .40, and the .69. With the .690" balls, it was
a little snug, but loadable with the Hickory rod that was in the rifle then. I had an opportunity to have an Osage rod made for
the rifle, and jumped at the opportunity. The old Hickory rod split some 10 or more years ago & was repaired with CA glue. Worked
& still have it as a spare.