Hi there, I've been trying to partially copy a duffel bag made by SDR Traveller This one - https://sdrtraveller.com/products/d3-traveller?variant=21489966678096 Mine won't be a double layer of cuben due to cost. Am going to use x-Pac for outer and 2 layers of HyperD 300 for liner fabric and internal pockets. I've been trying to prototype the pattern in some fake cordura before moving onto the pricey stuff. But I just can't get the zip to play nicely. I'm using a #10 YKK Aquaguard/Uretek zip and I can't get it to sit without puckering and pinching and pulling the fabric Dropbox of a few photos https://www.dropbox.com/sh/krukt66mkz0l8q9/AABpxLgF3VifmZ4kB0d1hv3La?dl=0 No idea how to embed photos from dropbox But hopefully here's some of bag to copy My attempts with a #10 YKK Aquaguard: 1st with a tighter curve: 2nd with a longer bottom, wider sides and gentler curve to give more allowance to cut off pulled fabric Still buggered 3rd with a standard YKK #5 coil zipper - still rubbish: On the SDR bag can't work out if it's an #5 or #8. It's definitely YKK as they mention that on the website but otherwise nothing to scale it by. They haven't cut notches into the zipper to help with curving it. It seems to be sewn quite simply. There is only one seam in the long sides/top/bottom piece of fabric - at the back of the zip as the design works by allowing the zip to curve over the side slightly. Have I got too many threads per inch? Not sure either how to start the sewing. 1st line of threads close to zipper coil itself is easier to control, especially when it comes to folding it back for the 2nd line. Or is it some elastic zipper possibly?