How do I measure the hardness of the silicone?

There are two types of silicone: solid and foamed (also called silicone sponge rubber).

Solid silicone is thicker than foamed silicone. The different scales of hardness are measured on a durometer by using the Shore Hardness Scales.

Also read:

What is the difference/are the differences between PTFE and TEFLON? How do I tell the difference between silicone and rubber? How do I measure the hardness of the silicone? What happens when TEFLON gets too hot? Which temperatures can TEFLON endure? Which temperatures can silicone endure? What is the difference between low value and high value ohm? How do I measure the diameter of a silicone tube? Does the diameter of the silicone tube affect the thickness of the content when the content is extruded out of the tube? What happens when TEFLON gets too hot? (1)