Quilting fabric has 60 threads per inch standard. I've found 60 - 65 to be the average. I have a tread counter and take it with me when I shop for fabric. I find most shops have mostly 60 threads per inch fabric, it's not on the bolt anywhere. When I do ask the manager /owner they never know. That's why I take my thread counter.
68 is what I look for premium quilting fabric. It doesn't shrink or ravel very much.