I really like the backings I got off amazon. I don't recommend getting the ones that you need the allen wrench for. apparently it's easy to damage the pin backs with those and some people wont trade for pins that they know have had them. I got
Congrats on starting your collection! Seeing how they fit on your bag, they might fall off from the rubber mickey head backing if an object inside pushes the pin too much outward. You can get locking ones like these to prevent that: https://www.amazon.com/SUBANG-Count-Locking-Keepers-Storage/dp/B01LYS7N9J
No problem dude! Good luck making your jacket and have fun with it!!!
Btw here's the link to the pin backs if you end up wanting them.
https://www.amazon.com/dp/B01LYS7N9J?ref=ppx_pop_mob_ap_share
There's another style of locking pin backs aside from this kind where it literally locks and you have to use like a needle or a small thin bar to actually unlock it, but I've heard that's a pain. some people also will glue their pins into the regular backs they come with to keep them from popping off but I cannot imagine how difficult that is to get off, and I like to rearrange my pins often so I think the ones I bought work perfectly
Probably just the short posts, but there are locking backs that you can put on pins that you can get on Amazon.
Edit: Here's an example you can only take them off if you pull on the backs and unlock them. I hope that helps with you finding more decorations!
I found some locking pin backs on amazon and they work really well!
These locking pin backs work great for me. Idk how they work, magic I assume. Haven't lost a pin yet.
Here you go- SUBANG 40 Pieces Metal Pin Backs... https://www.amazon.com/dp/B01LYS7N9J?ref=ppx_pop_mob_ap_share
You can find others but I got these from Amazon
You can buy locking pin backs. They're sturdier than regular pin backs, but you can still take them off to wash the hat.
This type are the best in my opinion. I've had terrible luck with the kind that use an allen wrench for tightening
SUBANG 40 Pieces Metal Pin Backs Locking Pin Keepers Locking Clasp with Storage Case https://smile.amazon.com/dp/B01LYS7N9J/ref=cm_sw_r_cp_api_glt_fabc_547CEGXBB9835AGZ8RW0
These are my favorites! Lost 0 pins at sunset!