[kwelstr]

This is interesting, they were using bast fibers from oak trees, or fibers that sit between the bark and wood of the tree. They are soft fibers that can be collected and weaved into cloth.

Wikipedia has an article (1) and pictures of modern bast fiber weaving in Norway.

1- https://en.wikipedia.org/wiki/Bast_fibre

[Tagbert]

Those same bast fibers from western red cedar trees were used by native people in the US Pacific Northwest area for clothing. Hats and cloaks were common. The clothes have a texture like soft paper and are water repellent.

[ncmncm]

Polynesians have long made "tapa" or "kapa" cloth from mulberry bark. It involved a great deal of hammering using a custom stone hammer with a flat face a couple inches wide and maybe 8 inches long, with a grooved surface. I expect the bark was laid over a flattened log.