The only linen available around here is about .008" to.012" thick. That might work for wiping your butt, but that's about it- about %$30.00 per yard, too.
The suggetons given are good, of course. There are a lot of good shooters here with their 'stuff' together.
Measuring cloth thickness in thousanths and getting simlar results from different people is almost impossible. Seems no one uses a pair of calipers on cloth in the same manner, with the same pressure. Different calipers give different measurments. I have 3 'pair' of calipers and get readings .004 different from my micrometer, with .003" difference between the calipers themselves. What do to?
Most or many of us up here shoot Denim- some have recently in the last year, switched to heavy ticking. I shoot both, depending on which rifle I'm using. Denim in 10 oz weight (10 ounce, not 10 thou) works in virtually everyone's rifle. It measures .0185" to .0225" depending on which method and tool is used to measure it. It it good material. The 8oz. Denim is too thin for any of my rifles, even the .40 and that one shoots a .3975" ball in it's .398" bore - it is easy loading due to narrow lands, wide grooves and and being a Goodoien barrel, 'factory' lead-lapped inner surface. I have a GM .45 barrel and it-too responds to exactly the same 'formula' used in most accurate rifles, a ball that is .005" smaller than the bore and a 10oz Denim or Mattress ticking patch, .020" or thicker.
The ticking spoken of is a mattress ticking I believe and is also available here. I measure it .001" thinner than 10oz. denim and it also shoots well & cleanly in all my rifles.
Here, the boys who inlude Taylor, Canvasback, Crispy and Neil of this site as well as Len, Clarence and Hatchet Jack - all use a descently heavy cloth patch with some form of water-based lube for shooting targets on the trail. Taylor used an oil, Neetsfoot Oil, all this last winter. None of us has to wipe the bore while were're shooting, whether it's a quick 20 to 30 shot day, or 80 shots- the bore never gets 'dirty', doesn't pick up or accumulate fouling. This is due to using a thick patch, with plenty of lube. Damp doesn't work.
Wet works.