It may not look like much more than a pile of black rags, but there's actually a lot more going on here.
Each of these costumes contains 48 meters (or 52.5 yards) of fabric! Mostly silks, since those drape so well. There are 5 seperate layers of costume here. And there were 29 wraith costumes made in total.
From Ngila: "I retrospective designed it which- - so in fact, there’s a drawing somewhere of the king, a king in an original, fully regal costume. And then I just redrew it, breaking it down more and more and more so that in fact the ring wraiths become- - there are vestiges of that original design as part of that costume. Totally subliminal. The costumes are built from the inside out. That’s a huge amount of detail and there’s a big reality to every single part of the costume. ... And it goes from quite light layers to really quite heavy woven- - not tight, because the textures and those sort of quite loosely woven, quite thick threaded silks."