The dial sweeps and the bezel travels, and those are not the same kind of movement. Reference 278341RBR is the 31mm Datejust in a combination of stainless steel and Everose gold with a domed bezel set with diamonds, and this configuration carries a slate dial with applied hour markers and no stones on it, on the Oyster bracelet. Slate is a sunray ground, brushed outward from the center, so its brightness runs high on one side and low on the other with the division sliding across a continuous surface as the wrist turns. The bezel is a curved band of separate stones, and what moves there is not a gradient but an arc, jumping from one setting to the next around the ring. One is a wash and the other is a sequence.
A sunray ground is brushed outward from the center, and that is what makes it sweep. The texture is worked into the dial blank beneath the finish rather than laid over the top of it, so it belongs to the metal and does not wear through, and because every line runs radially the surface can never hold a single value across its whole width. One side catches light while the opposite side holds shadow. The Everose markers applied to that ground are solid gold with height and edges, and since the surface beneath them keeps changing, each marker alternates between standing clear and settling back over the course of an ordinary gesture. Slate is also the one cool ground the reference offers, so those markers read as warm rather than merely as bright, which is not true of them on chocolate or on the matched rose dial. Outside the crystal the bezel is a dome rather than a flat ring, its stones set at continuously varying angles so that only an arc of the band is lit at any moment. Those stones are also the only ones on the watch exposed to the outside, since the dial sits behind sapphire and the bezel does not, which is worth knowing about how the watch will wear over years. Steel takes the case body and the outer bracelet links while Everose takes the bezel, the crown, the bracelet center rows, the markers and the hands, all of it solid rather than plated. The Oyster bracelet is three broad flat links, brushed on top with polished flanks, closing on a concealed clasp.
The watch does one thing beyond telling the time. The date changes instantaneously at midnight rather than creeping through the hours around it, the function the Datejust introduced in 1945 and takes its name from. Its disc is matched to the slate ground, which is a harder match on a sunray dial than on a flat one, since the surrounding surface has no single brightness for the disc to agree with and the compromise has to hold at both ends of the range. The frame is drawn for a 31mm dial rather than reduced from a wider one, so it stays clear of the markers at its shoulders, and the Cyclops lens above it, fitted to the model since 1953, enlarges the numeral roughly two and a half times. Correction runs through the winding crown at a dedicated position and leaves the hands where they are. The movement is self-winding with a power reserve of approximately 55 hours, built for a case this narrow rather than carried down from a wider one, since a smaller barrel stores less energy and a lighter rotor takes in less of it from the same arm. The crown screws down against the case, and the bracelet folds shut on itself.
The Datejust has been in production since 1945, when it became the first self-winding wristwatch to show the date through a window on the dial. The 31mm case sits between the 28mm Lady-Datejust and the 36mm original, and the 278000 generation replaced the 178000 series in 2018 with a revised case and bracelet. Rolex registered the name for its steel and gold construction in 1933, on the reasoning that steel supplies the structure and gold supplies everything the eye takes in. Everose arrived in 2005, and most of the dial colors developed around it since have been warm ones, since warmth was the point of the alloy. Slate is one of the few exceptions and has been kept across generations rather than rotated out, which is unusual for a grey. Within the generation, 278341RBR is the steel and Everose reference with a diamond-set domed bezel, and 278241 offers the identical dial under a plain dome. On the plain reference this is the least decorated watch available. Here the same dial becomes the only undecorated surface on a watch whose case is set, which is a considerably more deliberate thing to have chosen. Slate is one of three unset grounds on the reference.
The buyer for this wants a set bezel without a set dial, and slate is the ground that makes that read as a decision rather than as an economy. A pale dial under a diamond bezel looks like the gem-set version of a plain watch. A dark one looks like it is hiding. Slate does neither, sitting at a value where the dial is clearly present and clearly unornamented, so the contrast between a set case and a plain face registers as intentional. The Oyster bracelet supports it, three broad links built for daily wear rather than for occasions. The sunray finish is what keeps the dial from being dull under all that brightness at the rim, since a flat lacquer at the same value would simply sit there. Buyers arrive here from the plain-bezel slate having decided the watch needed presence at distance, and from the gem-set dials having decided that setting the face as well was more than they wanted. The second group is the larger one.
