Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4835912.

A very useful tool for holding books open with one hand. Other designs that I found had circular thumbs holes that were uncomfortable and were very thick and blocks the view of some words. This holder has an oval thumb hole for a more comfortable fit and is thin but strong when printed at 100% infill. if you have large hands it is easily scalable to your liking