In those songs, what you gave DrTomas, there are mani song (dainu) variations like for one song there is said that mother sew a brown skirt, for other flaxwaste(pakulu) skirt, for other skirt to wear under the armour or just armour skirt, for another armour coat. Or even better - bean skirt

but this one could be poethical denomination for metal rings from which made chainmail.
OR this bean skirt could be used for some kind of gunpowder weapon protection. Whatever. No one really knows because there is massive amount of songs (dainas) and their variations.
In the middle of that page they wrote that those experimental "war skirts" were made based from "dainas".
And first examples (edit: examples of this kind of skirt) were found in today what is Estonia (13-14 century), Poland (12-13 century) and Latvia (14-15 century).
bla bla bla...
And in the result they made medium heavy, flexible, air penetrable (sorry nothin comes to my mind to describe that action

) and absorbs power of any hit. Below is said that effect is same as western made gambesons.
So if they say so, it must be true and tested i doubt they are lying.