Heres the blue ticking from Joann fabric .015-.018 give or take
http://www.joann.com/utility-fabric-...ing%2B&start=1
well it it looks like the samples I bought aren't gonna work out , my new to me rifle came yesterday and to my surprise a very tight bore with shallow grooves , I couldn't even start a .493 RB with a .015 patch even smacking it with the short starter looks like it's gonna take .010 material which is ok they had the red ticking in that thickness same for the 40 wt drill cloth and their version of linen .