The next superhero film to hit theaters will be Wonder Woman. Many Amazonians from Themyscira appear in the movie, including (obviously) Queen Hippolyta. Redditor The GiantLemoncake made a costume based on the ensemble and used Profoam for the build. I haven’t heard of the material before, but she explains it’s kind of location based for her:
The material is called Profoam, it is similar to EVA foam but we hardly get good EVA foam in Germany. Then it is primed with Flexipaint and painted with wax-paint from pébéo.
With the painted finish, it very much looks like it’s metallic armor.