Hera I will add some extra info on my trip in Japan in May 2013. Specifically I am posting a brief video on a lesson of naginata run from the wife of Sumi sensei.
I do not practice naginata and I know very little on this martial art but I was very catch from these young ladies very commited in their practice.
Sumi sensei describes to Pomero sensei the bamboo characteristics needed to make a good shinai
Bamboo cut and ready to be transformed in shinai
Then are shaped (first part next video) and then tsuka is shaped (second part of the video)