About characteristics and shapes

• What are the characteristics of artificial fibers?
• Please tell me the differences between Outerfiber™ and Innerfiber™.
• The handle shape of shakehand blades has variations such as FL and ST. What are the differences?
• The blade shape of Japanese penhold blades has variations such as S and R. What do they mean?
• What is the reaction property?
• What is the vibration property?
• Please tell me about the gravity center of the blade.