I know there are those with a huge zipper, but I don't feel confident enough to make a perfectly straight line with a zipper. My sewing skills tend toward the Modern, Modern Art if you know what I mean. My mother could do it with 100% total precision. That is probably why I do not do anything with 100% precision. But I digress.
From Regina's Quilting Studio photo
Meanwhile, I will ask the superior brains of women, have you ever used a zipper? Did you buy it or make it yourself? Have you ever used the dowel and snap system? Where did you buy your leaders from? are they marked with a lot of increments? What are the increments?
Mine are plain, but I can mark them if I have help. Maybe, I can't cut anything straight or the same length twice.........