blahel, I've been quilting for nearly 16 years now and my ruler slips at least once a day. Like Patrice, I sometimes get in a hurry and don't pay attention to how I'm holding the ruler under my hand and...whoops!...there is goes. I've gotten pretty good at recognizing when it happens though. I used to just cut it so fast I didn't realize it had slipped and then I'd wasted a strip of fabric. I'm more careful to be mindful of how the ruler is acting now. I could probably make a bed-sized scrap quilt from all the strips I've screwed up over the years! :lol: