What is this material?

[Husfixardoktorn]

Hello! Not sure if this is the right forum and it might be a silly question, but what is this material that was used for wallpapering? Likely built in 1965. Thanks in advance!

 

[JSE]

Treetex!

 

[Husfixardoktorn]

Treetex!

thanks! Follow-up question, can it be painted with water-based paint or does it swell since it is so porous?

 

[Jonatan79]

Not paint at all unfortunately. Apply renovation wallpaper first if so.

 

[JSE]

No, painting directly on it is not fun.. Put some canvas or renovation wallpaper first.