Does anyone know what non-woven fabric seedling bags are fulling biodegradable?

I have just found out about non-woven cloth seedling bags.  They all claim to be bio-degradible, but reading up more they can be made from polypropalene,  PLA or natural fibres like Jute.  Which suggests they just break down into micro/nano plastics.
https://www.biononwoven.com/info/what-are-biodegradable-non-woven-grow-nursery-102879641.html

Does anyone know of bags that are made from all natural fibres and do actually fully biodegrade?

I think you could make little bags out of wool.   They could be knitted or felted.  There is usually lots of wool discarded around shearing time.   I made lots of garden twine out of wool that would have otherwise beed used as mulch and let to degrade.  

I think wool would be a good choice - it holds onto moisture and insulates thermally. I'm thinking felt would be the easiest/quickest to make or get hold of.

Newspaper:

https://permies.com/t/22338/Origami-Newspaper-Pots

There might be concern about the kind of ink used.

I got some of these seedling bags and a grow mat as a gift:

https://www.floatingpeaks.co.nz/shop/garden-gift

I liked them but they might be on the pricey side. I've often thought about felting some of the many bags of wool I've got into matting, but just don't have the time for it at the moment.