Rolex case backs are notably understated compared to many other luxury watch brands. Most modern Rolex Oyster models feature a smooth, plain stainless steel or precious metal case back with no external engravings or markings visible to the wearer. This minimalist approach is a distinctive Rolex characteristic, and the presence of elaborate engravings or logos on the exterior case back of a standard Oyster model is often considered a potential warning sign. Notable exceptions include certain vintage models, some Rolex Sea-Dweller references, and commemorative or special editions that may feature engravings.
Historically, Rolex applied a green hologram sticker to the case back of new watches as an anti-counterfeiting measure. This sticker, which featured a Rolex crown logo that appeared to shift and shimmer when viewed from different angles, was commonly found on watches sold from the late 1980s through approximately 2007, when Rolex discontinued the practice. The presence or absence of a hologram sticker can sometimes help approximate the era when a watch was last sold, though stickers can also be removed, replaced, or counterfeited.
Inside the case back, which requires proper tools to open, Rolex typically engraves internal reference information including the case reference number and sometimes factory markings. The interior engravings and the quality of the case back finishing are commonly examined during professional authentication. The case back gasket and the precision of the case back threading are also considered indicators of authenticity, as Rolex is known for extremely tight manufacturing tolerances in their Oyster cases.