prepreg on both sides with approximately 20-30 layers of graphite that make up the 2mm sheet. It is then heat compressed to fuse the layers together. If you actually had a piece of my product in you hands, you would know its structural integrity is top notch. It's funny how people complain about it not being shiny enough or that the finish isn't "pretty enough". And now that its too shiny, gee..., "it must be fake" LOL. But I must strongly disagree with you accusing me of producing fake product just because of a finish that you see in a picture.