This is a simple edge profile for your shelfs.

Designed and printed in PETG for springiness, with a .6 nozzle, but I bet a .4 will do the job aswell.

It is made for 12mm shelfs, but have a spring effect, and can easily be scaled to needed size.

The profile is 100mm long, so before you slice it, change it to the procentage/length you need.