David- if you use calipers to measure cloth, Denim, that is 100% cotton denim is available from abourt .012" to .030" thick. some makers of denim use per ounce weights, ie: 6oz., 8oz., 10oz. and 12 oz. I have not seem any 14oz. as the 12oz. seems to be the thickest denim used in very heavy trousers and jackets.
Which to use depends entirely as LB says, on the ball size. You should know the bore size, groove depth and ball size. If not groove depth, then at least ball size and bore size.
I have found best results when the cloth is double, ie: twice the thickness that the grooves are deep. With normal .010" to .012" rifling, I like .0215" to .025" in ticking or denim. This is for use with a ball that is .005" smaller than the bore. With .010" balls, I like to use thicker patching yet.
With a nicely raduised crown, it is not difficult to load. My daughter and wife Tracy, have no difficulty loading a .022" denim patch with a .445" ball in Tracy's .45 GM barrel that has a .450" bore. There is never a need to wipe the bore during a day's shooting as each time it's loaded, the bore gets wiped. The fouling cannot build up from shot to shot & stays the same, all day.
Rougher bores can be difficult at times, but usually benefit from thicker cloth with smaller balls, ie: .010" smaller, with a .025" to .030" patch in .010' to .012" rifling.
Denim must be washed before being used. I usually run it through the washing cycle twice to make sure I get all the sizing out. I measure cloth after it's been washed as sizing can scew the reading.