My belief is there was no standardized patching material. And they used what they could find. Sure they likely found a favorite for their rifle with what was commonly available.Regarding patch thickness, those are great questions. It also makes me wonder what common patch cloth would have actually been like then, right at the dawn of machine textile weaving, both in weave density and in material thickness. As well as just consistency. I mean, was there a standardized "patch cloth" they had access to, or was it kind of a get-what-you-can type of situation?
(Caveat, it's been a while since I dove into many of them so there may be new info I'm not tracking on).
If you look at trade lists, store inventories or even estate listings there doesn't seem to be "one type of cloth" that was constantly listed, that could be construed as being used for dedicated patching. Hemp was a very common cloth listed. Calico (was it just a pattern type or a material type?). Muslin, but it was cotton and more expensive. And wool stroud. Stroud would have been too think for a rifle unless the bal was more undersized (but would work in a fowler) and likely more expensive.
Pillow ticking was used for beds, but was it really available at a trade store on the frontier or at rendezvous? So in my mind that would leave hemp cloth. And did they have a particular "feel" they liked to get close to their ideal thickness? Or just got what they could, would shoot the rifle and see how it shot and decided "that'll do". Does make you wonder.
Just my .02
