#4 invisible / concealed nylon closed-end zippers are heavier-weight than standard invisible zippers. When the zipper is sewn into a garment, the
Ykk Fabric Zipper
Pulling Teeth: Tips to Shorten Zippers - Threads
7, #8 Heavy Duty Closed Bottom Zippers
Invisible Make-A-Zipper - MyNotions
White Zippers
How to Pick the Right Zippers for Your Project
Natural Zippers
Pillow Zippers
Reasonable Price Any Length Closed End Invisible Zipper, High