I believe from my experience of seeing this trim, it's really just gold pvc thats lightweight enough or has enough natural stretch to go around edges. I've seen both folded over edges or clean edged and also unfinished edge or cut into strips and sewn on cause it's easy to do...etc.
I've only ever seen anything similar at Joann's in their trim section, it's like a gold belting...but it's already glued down, you could try cutting it in half to see if it is useful in any smaller pieces.
Anime USA 2015...Halloween!
Steven Universe- Rose Quartz Gown version
Evangelion- Asuka Langley Soryu Yellow Sunddress
Magic Night Raye Earth- Ferio Yellow Shirt Version
Yuri Kuma Arashi- Kureha Bear Form
Yuri Kuma Arashi- Kureha OR Lulu School Outfit
Artist's Alley Hopeful....We'll See
Awesome Con 2016
Deadpool/X-men Comics- Siryn...not sure which version yet...
DC Comics- Raven Either Teen Titans or Original Comics version....