The set version of this ground changes arrangement at every size it reaches. At 28mm it is twelve settings with a gold Roman nine carrying eight stones; at 31mm it is twelve settings and nothing else; at 36mm the name covers two further dials, one with a pair of gold numerals at six and nine set with twenty-four diamonds and one with baguette-cut stones at those positions. Four arrangements, three sizes, one name. Nothing in a listing distinguishes them, so the reference number is the only reliable way to know which dial is being described, and a buyer comparing rose set dials across sizes is comparing four different objects. Reference 278275 is the 31mm Datejust in Everose gold, carrying a fluted bezel, and this configuration pairs a rose dial set with twelve diamonds in gold settings, with no numerals on it, and a President bracelet.
The case is solid Everose gold with the fluted bezel cut into the metal rather than applied as a separate ring. The dial is rose, pitched to the case, and twelve round diamonds sit at the hours in gold settings matched to it. On a matched ground the stones do something they do nowhere else on the reference: they are the only element on the entire watch that is not gold or a version of it, so they carry all of the contrast the dial has. The mounts disappear into the ground almost completely, which means the stones read as bright points floating on the surface rather than as objects set into it, and the ring holds together as a circle of light rather than as twelve pieces of hardware. That is the opposite of how the same twelve settings behave on a dark ground, where the gold mounts are clearly visible and each stone reads as a mounted object; the ground decides whether a setting looks like jewelry or like light. The President bracelet is semi-circular three-piece links in the same gold, rounded across their width, and it is the only bracelet this reference offers. The result is the most monochrome watch the model builds with the brightest possible interruption in the middle of it. The fluted rim adds a third register to that: cut gold returns light in a rapid broken pattern, the stones return it in twelve fixed points, and the ground returns it as one continuous warm field, so the watch has three different kinds of brightness arranged in concentric rings.
Hours, minutes, running seconds and a date advancing in a single step at midnight. The self-winding movement in the 31mm case holds roughly fifty-five hours of running time, matching the 28mm references rather than the 36mm ones. The dial adds nothing beyond that and is read by position alone, since a diamond in a gold mount says nothing about which hour it marks and the ring works only while it stays even. The date window at three is the single break in it, and on this ground the white disc competes directly with the stones for attention, since both are far brighter than anything else on the watch. That is a busier lower right quadrant than the plain versions of the same ground produce. What the setting solves is the legibility problem the plain rose dial has: applied markers on a matched ground need direct light to register, and diamonds do not. This is the version of the dial that can always be read, which is a more practical argument for stones than the reference usually offers. Elsewhere on this watch the setting is decoration added to a dial that already worked; here it is the element that makes the dial function, which is an unusual thing to be able to say about twelve diamonds.
Rose is built on Everose cases and on nothing else, at every size and in every form the catalogue makes. Plain, it exists at 28mm and 31mm in two marker arrangements each; set, it reaches 36mm as well, with a different arrangement at each size. Within this reference the ground appears three times, more than any other here, and the set version is the only one of the three that puts anything on the dial other than gold. It is one of nine grounds across eleven configurations, seven of them set with stones, which makes this a predominantly gem-set reference rather than a plain one. That is the normal condition of a solid gold Datejust at this size and the reverse of the two-metal cases, where unset dials outnumber set ones on every reference. It is also one of five solid gold Datejusts at this size, all of them President-only, and 278285RBR is the same case with a rim set with diamonds and an identical dial roster. Between the two references a set rose dial in solid Everose at this size therefore exists in exactly two watches, since the bracelet is fixed and this ground comes in only one arrangement at this diameter.
This suits a buyer who wants the warmth of a matched gold dial and something to look at as well. The plain versions of this ground give up all contrast in exchange for coherence; this one keeps the coherence and buys back a single point of brightness twelve times over. Nothing else on the watch competes, so the stones read as the entire ornament rather than as one decorated element among several. Anyone who wants the dial without them should take the plain rose, built here in both marker arrangements. Anyone who wants the stones on the outside instead should take 278285RBR, where the same dials sit under a set bezel and the balance reverses. And anyone who wants this ground at a larger size will find it only in set form, in an arrangement that is not this one, and on a case that is not solid gold in two of the three instances.
