SYNTHETIC VELVET.  
I bought these because they were advertised as velvet, and because they came in pretty jewel tones  greys. Sadly, they do not live up to their advert. The fabric is a cheap, synthetic material, like faux horse fur. In natural light, there is  no camouflaging this. If you want true velvet cushions, look elsewhere.
On the less negative the colors are beautiful. The design is nice, also. If you’re going for tacky fake fabric chic, you may love these. I, do not.
Other plus my cats don’t mind them. Probably I’ll use these fake velvet covers to line their beds, or vet kennels.