I owned Thule backpack for almost 10 years or so. It is by far my favorite and durable one. After some time my zippers started to break which is shame, because I absolutely love how they feel and look.
I could not find them anywhere so I purchased small roll of TPU and got designing.
It is heavily inspired as you can see, just optimized for 3D printing. Originally I wanted to utilize the metal part for durability, however it is not ideal and was worried about how well it would hold with overprinting so I designed it from scratch.
For the inside part I would recommend to use ASA if you plan to wear it a lot (due to UV), however I did not have the roll and went for PETG, PLA should be fine as well. In case they fail, I might tweak the design a bit or print it from other material.
The flexible outside I printed from TPU so have the same feeling as original and I have to say it is very close.
PRINTING