I've seen the same PRINT on different qualities of fabric, but I don't believe it was from the same manufacturer.
I bought a bunch of the Tim Holtz fabrics from Fabric.com, but ran short and found some more at Joann's. When I got the Joann's fabric home I could tell it was different. The print looked just as clear and the coloring was nearly the same, but the Joann's fabric was thicker and about 2 inches narrower. I actually liked the hand of the Joann's fabric better, but once it was all mixed into the quilt together I couldn't tell the two apart anymore.