Some fabrics have more sizing that others. Thus, I've had some brands gain a thousandth, while others lose a thousandth - most lose. The greatest change was .002"- can't remember what it was. The mattress ticking, seems to me, gained .0015" due to fluffing. The difference is usually not great. That red/white/blue of a light blue background Railroad mattress ticking is wonderful patch material. It's very soft, easily compresses into the bore and shoots splendidly in LB's rifle, Darrel's, Kimm's Taylor's, Lens, and every one of my own, from the .32 to the .69. Good stuff. It measured .020" with my mic, but .0235" with the calipers.
Note, as I've said many times before, seems everyone's calipers or mic records a different # on the dial or tube. Taylor's mic is .001" different from mine. I have 3 sets of calipers, but always measure the same, pinching the tines between finger and thumb, not using the push button. My calipers give 3 different measurements, stating .002" 9on most materials) different from my mic.
Like Gene - I also like the 10oz denim. It is good, usually uniform and for me, runs .0220" to .0225" in thickness witht eh calipers and a full .020" with my mic., same as the "thicker by caliper" ticking.
8 ounce denim runs .017" with the mic and .020" with my smallest measuring dial calipers (best set). 8 ounce denim will shoot in some rifles, but does not seal in others and scorches badly, throwing accuracy out the window after only 4 shots. Even though it does this, it does not make wiping required at any time, it's accuracy is just lacking due to being too thin. If you wipe every shot, it will work - I guess as the inner bore condition is changing, must be - but is too thin for me and those people I shoot with. It is strange that the lowest pressure gun I shoot, the .69 (with it's squib load of 82gr. 2F) is the one that accurcy fails in with the 8 ounce. The .58's hate it right from the get-got, but shoot the thicker patches just like every one of my guns.
As to different guns, we've found that material from .020" (micrometer compressed 'brrrrrt' with the ratchet) or thicker will shoot in every rifle we know of (even Rice & Getz rounded grooved) with a ball that is .005" or .006" under bore size - up to bore size. When going larger than bore size, a thinner, .015" to .018" will work just fine.
I run the 3 or 4 meters of new material through a washing cycle with a normal soap amount, then run a complete cycle again without soap. I suspect the second cycle would not be needed if I hit the 'second' rinse button - a suggestion from my loving wife.