[Leather Craft] My technique for attaching Zippers neatly. 

This time, I've summarized the focus points when I attach zippers. And I'll show you how to make " a zipper ruler" . A zipper ruler is my original tool that helps me attach zippers neatly when I make a round zipper wallet. I always made it using JW-CAD(Japanese free cad softwear).
I am sorry for the late response to your request. Other comments include "have trouble with zippers" and "I want to make a round zipper.". This is just an example, but you don't have to make a template like a wooden mold, so you can try this method easily.
A zipper is a part that stands out, so if it gets distorted, it will look so bad. It may affect not only the looks but also the function of opening and closing and durability. I am still studying. If you have an better idea, please let me know.