I went to Joann fabric store yesterday to look for some likely patch material . Took the calipers and found some .015 blue stripe ticking also some .018 white denim and last .020 canvas cloth . Bought just a 6" wide piece of each . I had heard/ read that most folks wash the fabric before hand and I figure a good idea as I normally stick it in my mouth using spit as the lube . Threw it in the drier till try went and measured them all this morning and boy did it change . The ticking is now .020 the denim is .030 the canvas is .032 that was all with the same compression on the caliper as before. Is this a common thing I expected a little thicker but at .030 I don't think I'll even be able to use those two . Do you normally pick your thickness before or after you wash ?