Pool & Carom
Popular hardness barometer.
The hardness is tested with static hardness measurement. This measurement does not take time and speed of acceleration into considaration.
Elasticity stands for bouncing force generated when a tip impacts a cue ball with the speed of acceleration.
When elastlicity of a tip gets higher, the contact time of the tip and cue ball gets longer so that you can have more spin on a cue ball and feel bouncy shot feeling.
On the other hand, the contact time is shrotend as elasticity gets lower. So that you can get more solid shot feeling.