holy-what

Hello. I am considering buying a 1001xx, but i'm a bit lost on the size I have to choose. I need 41 cm on the half waist to be confortable. Reading product page: https://www.ware-house.co.jp/?pid=132358411 I would need a size 31, but after shrinkage, the 82 cm would turn on 76 cm. Do they stretch back to original size?

Hi! Wich are the differences between 13,7oz and 15,5 oz fabric please?