yes ruler are not all equal. there are only 2 brands of rulers that have what they call line-of-site. they are Ominigrid and Nifty Notions(which give to breast cancer) there are small breaks in the line where you line the edge of fabic up on and then you are consistent. I have complete line of Nifty Notions rulers plus extras in my travel bag. I have interchanged these 2 brand and it has worked fine.