High contrast marking of metals is used in a wide range of industries. Fiber laser marking of these metals provides non-contact marking with no consumables, offering many advantages over traditional methods of metal marking. The laser creates a permanent mark on the material surface combining heat and oxygen with no noticeable ablation. The focussed beam of the fiber laser in combination with precision control of the heat input is able to treat small areas of the material surface evenly and consistently, which is critical for producing black anneal marks. The marks are highly legible which is ideal for marking serial numbers or small data matrices where traceability is required. This paper reports the experimental study for producing black anneal marks on various grades of stainless steel using fiber lasers. The influence of metal surface finish, beam quality, spot size diameter and pulse duration are investigated for producing both smooth and decorative anneal marks.