Here is a sparta pin that you can attach on a bag or on any fabric thanks to a pin.
3 pieces are needed to built it : base, plate, pin between 12mm and 32mm.
To build it, attach the pin to the base. The pin's opening side should be at the back of the base (with the smallest hollow).
After, clip the plate on the other side of the base (with the biggest hollow).
I haven't used glue to fix them together. I printed pieces on an mk4 with 0.2 mm.
The author marked this model as their own original creation.