I need three or more identification cards to be displayed from a lanyard around my neck.  One is a smart-card that must be physically presented several times a day.  These holders are designed in single, double or triple configuration.

You can print the one STL for a single card holder, the one for the double card holder or the two part STL for the triple card holder.  It's hinged at the top for visual access to the center one.  I used straight nails cut to the appropriate length for the hinge pins.

The single and double can be plated with the pocket up and require no support.  The hinged parts for the triple require careful plating and some minor support.

PLA or PLA+ worked best for me.

These are designed with OpenSCAD so the dimensions can be tweaked.