Hello,
i got some PCB′s ordered with a copper layer thickness of 105um. I had some doubt because traces kept breaking on the pcb and cut of a small piece off on one of the boards. I had to remove the solderstopmask with a knife and measuered the thickness in the attached picture. 
I measured a thickness of about 80um, did i make a mistake measuring the thickness like this or did the manufacturer use 70um copper?