Photoelasticity is a fantastic way to see what is usually invisible in mechanics: strain and stress. It can be used for educational, scientific, industrial, and even artistic purposes. However, it is not always easy to understand [how it works](/photoelasticimetry), with [which material](/method-make) and [how to image](/method-image) it. The purpose of this wiki is to give an overview of the different methods to deal with photoelasticity: