These items are rough and bulky and thus, you need several layers of mod podge to keep these on wood and to preserve it. You can use this on different materials, not just wood but it can save you time to learn how to use mod podge on wood as it is the most common.
How to identify teak wood
Wood plank stamp concrete
Mid century wood stool
How to Transfer a Photo to Wood with Mod Podge Photo on wood, Mod