Help From The Community

Zippers have always been a mystery for me. Don't get me wrong, I see them discussed in some very influential publications. However, I find it hard to grasp the concept of how they are resized, assembled and installed properly. Additionally, the advantages and disadvantages of zipper metals and materials would be interesting to know. What tools are required to make a custom zipper? Has anyone come across a good resource on this topic? Perhaps a good youtube video has covered it...or maybe it can be a topic that can be discussed in a leathercraft master class if the demand is there.