Different Feather Shapes. How? Why?

Hi my name is Duncan Chau, RSL International CEO.
What separates an expensive shuttlecock to a cheap shuttlecock is the shape of the feather piece. Why are there full rounded shape and some are not full rounded shape feather piece? Let me show you why!

[@lauweijie98]

this was really insightful! learned something new today. thank you

[@subashghimire4532]

Hello,
I was interested in those machines that could be used by hands to make the shuttlecocks. How can one get machines and cutting mould where feather is punched? Can you help in any ways to get those machines specially hand operated? Or any idea would be of great help!!