>>96365994
There are other psycho-plastics used by the Eldar, yes. Wraithbone is their most valuable since it requires an entire sub-Path of the Seer to learn how to create and manipulate it, and it's the primary armor they use on their vehicles and what they make their weapons out of. But we've never been told what all their other psycho-plastic materials are or how they work.
>>96367179
>shitty 10e faggot lore
No. Wraithbone is grown from the Warp itself by Bonesinging. We've seen it done in numerous novels and video games. Hell, even the miniature of the Bonesinger shows the unit doing exactly that.