The first and only fully 3D printable suspenders clip ( at time of writing) :)
FreeCAD file provided for your customization needs.

I needed something to hang an apron so I thought that a suspenders clip will do the job nicely. But I am on a ship, there are no shops here so I needed to make one (well several but ...) I searched the internet for a suitabl model but found none. So I made my own.
Designed so the latch and upper jaw (not sure for correct names here, please suggest proper ones) are printed in vase mode with 0.8mm external perimeter width, lengths of 1.75mm fillament used for hinge pins. A little bulky but works for strength.
I hope You find it usefull for your projects. Please post your makes, comments, modifications...

Edit 22.11.2021: After using the apron for some time it turned out that the clip is not very strong and can easily be pulled from the fabric. So I made a stronger version of the Upper Jaw and corresponding Latch. LatchForUpperJawStrong is printed the same way - on the side, vase mode, 0.8mm external perimeter. But the UpperJawStrong prints normally (no vase mode), on its side, 0.55mm external perimeter, 3 perimeters, 20% gyroid infill.

KissSmart

No

No

0.2

20% gyroid

Print Latch and UpperJaw in vase mode, side orientation, 0.8mm external perimeter width, 5 bottom layers. Adjust PrusaSlicer SliceGapClosingRadius (see screenshot) to something less than 0.0049mm for the ribs in the UpperJaw to slice properly. Drill hinge holes with 1.8mm drill. Or print with 0 bottom layers if you dont have this small drill available. Acquire such drill ASAP :)

Drill holes for the hinge pins in Latch and UpperJaw. Use lengths of fillament as hinge pins. Check proper operation, adjust parameters in FreeCAD if not working properly and reprint. Heat and squash pin ends to secure them in place.

Took some iterations to adjust the dimensions for proper click.