agree! I know that comes as a shock. I also disagree with Dutch Schoultz's advice of using a crush fit. It doesn't solve the problem of variables from one person to another. I believe a " crush fit " as a standard was thought up by people who have the luxury of owning a micrometer with a " clutch", that clicks when you exceed its maximum pressure. If you use such a micrometer, the clutch will provide some consistency. Whether that is a crush fit or not depends on how the clutch is set.
I prefer to tighten my micrometer until the fabric can be pulled out of the instrument, but comes out slowly. I can repeat that tension fairly reliably, and I can practice that using feeler gauges or some fabric, or paper, like a business card, that has a known thickness.
If I try for a crush fit, the number of threads per inch of the weave affects how much I can crush the fabric, as will the kind of cotton, or, heaven help me, linen, or other fabric I might try.
I know from personal experience that the .005, and .010" patches I have bought made by the old Ox Yoke company, when damp, could be crushed down to about .002" of an inch, but that actually told me nothing about their performance in my gun. ( .45 cal.[.451 diameter bore] rifle with scratches for rifling!, and a .445" diameter ball.)
All my strength on the barrel of my old micrometer showed was that both patch fabrics were too thin for what I was expecting them to do. I eventually settled on .440" balls, and .015" thick patches, and 55 grains of FFFg powder. That combination proved very accurate out at 50 yards. Using the clutch micrometer, those thin fabrics measured pretty close to the advertised thicknesses.