A typical thickness is 0.01" and with a stiffness similar to thin card. The colour is unimportant — green is common but other colours (such as red or grey) are available. While the photo may make it look like thin felt, it is actually smooth and firm.
Two questions:
1. What is it for?
2. What is it called? (What is its "common" name?)
![Image](https://i.imgur.com/55rNbuO.jpg)
(My image)
Julian F. G. W.