My experience with the ‘print-in-place’ bag clips was pretty disappointing, as they often break and don’t have much clamping force. After countless trials I realized that only separate spring can provide reasonable function.

The required spring flexibility must be provided by PETG or another strong filament. PLA is not suitable for the spring due to easy deformation and “memory effect” after applying pressure.

Bambu PETG-HF works fine, however I achieved the best results with Bambu PETG-Translucent that seems to have the highest elasticity. To maintain different materials, there are three springs available, each with different clamping force:

There might be other filaments suitable for the spring like nylon or similar, potentially PLA TOUGH could work too. Please share your experience when you have access to such materials.

Assembly instructions:

1.    Insert the spring into the bottom recess of the clip
2.    Push the spring until it snaps into the upper recess
3.    Ensure proper fit by gently moving the spring back and forth
 

Note: before applying the clip on sensitive clothes, ensure the teeth will not leave any marks!