There are no marks on this chair however, some fiberglass armchairs by Herman Miller were without markings. According to the Herman Miller website, early chairs had only a sticker which were frequently lost. One of the clues that an Eames chair is authentic is “Visible Fibers: Real vintage fiberglass shells show a distinct, textured surface with visible, random fiber striations. Smooth, uniform plastic is usually a newer polypropylene or plastic version.