Dear Researcher, Please have a look at the attached article and its references:
A Miniaturized Tree-Shaped Fractal Antenna Printed on a Flexible Substrate: A Lightweight and Low-Profile Candidate With a Small Footprint for Spaceborne and Wearable Applications
Farzad Mokhtari-Koushyar ; Peter M. Grubb ; Maggie Yihong Chen ; Ray T. Chen
w.fl connectors are only about 2mm square and snap together strongly enough to act as a functional snap to hold clothing parts together. Good Luck with your project.
Solder is probably the best but I think it will depend on the location and the function of the fabric in the local area of the garment. Have you seen Adafruit's Flora series devices? They are made to be sewn into wearables and they have a good assortment of modules for prototyping. Another option is to have your own PCBs designed. Flexible PCBs are available and could be incorporated into sections of the garments that are typically more rigid than the rest, e.g. collars or button seams.
You may also want to look up the u.fl as well. It's a little bit bigger but there are many more standard items that use it so you'll have a better selection of options.
Soldering is not deasible in my case because my fabric conductivity is going to melt. I will look into sewn options first. Thank you . I hope you won't mind me contacting you again