No - I don't block my quilts -- -if they're truly squared up when I put it on the machine, then it'll be tweaked maybe only a little bit. I can't imagine putting that much water on a customer's quilt!!! Maybe, if you find that your quilt is wonky, then put it in the washer with one of those sheets that stops bleeding and get it wet, then block it. I've never had a quilt that was that wonky!