A-Frame Shelf Item Backstop

This is a simple model I made to keep paper we have displayed on our a-frames, (a type of freestanding shelving unit where the two sides tilt back to hold items on it, which makes it look like an "A".) because they are always falling through the gap between the shelf and the back.  The gaps on the particular A-frame I made this for are 3-5mm, so I made it 3mm.  It's a little jiggly in the 5mm gap, but won't fall through.

There are two models here.  The smaller one I made first.  It is for pieces of paper.  The larger one is a modification with a shorter back, but longer and wider base to hold brochures.  They work pretty well if I say so myself.