The DB28 was recognised with the overall top prize – the Aiguille d’Or – at the 2011 Grand Prix d’Horlogerie de Genève (GPHG). Since then, the line has been a canvas for De Bethune’s experimentation with materials as well as complications. The "Kind of Blue" Tourbillon, created in a limited series of five, is one such playful variation on the DB28’s aesthetic, imbued with the brand’s lightweight tourbillon, first developed in 2008.
The 42.6mm case is crafted from grade 5 titanium that has then been blued and mirror polished entirely. Similarly treated are the brand’s signature and skeletonised floating lugs. Even the crown, with a knurled end, has been similarly blued and polished. Sandwiching the case on either side is sapphire crystal scratch resistant to 1800 Vickers.
The DB28’s particular aesthetic, characterised by the delta-shaped mainspring bridge, had been an essential factor in the watch winning the Aiguille d’Or. Here, that dial-free appearance is also given the “Kind of Blue” treatment. The satinated blued bezel, with contrasting applied plot hour markers, gives way to the to bridge that anchors the two mainspring barrels that power the manually wound calibre DB2019. The bridge, with a tiered form, is not just blued and polished, but adorned with the gold leaf and applied plots to approximate the Milky Way, another recurring decorative motif for De Bethune. Mounted on the bridge are the rose gold hands.
This blueing is applied to the baseplate as well. However, here, owing to the underlying Côtes de Bethune striping, the shade appears a bit lighter. This serves to give an impression of depth to the dial side appearance. The base of the tourbillon carriage is also blued and mirror polished, as are the arms of the tourbillon bridge and the silicon escape wheel. In fact, the balance wheel, also crafted from silicon, is blued too, with white gold weights. The tourbillon, De Bethune’s lightweight and antimagnetic take on the regulating device, features a cage made of a titanium and silicon and completes a rotation in 30 seconds. It features a delta-shaped marker, so the wearer can track the tourbillon’s performance.
The fairly minimal movement side of the calibre DB2019 is also evenly blue, albeit of different shades owing to the variety of finishes here. For instance, the rim framing the movement – which also hosts the discreetly placed power reserve indicator that tracks the five days of reserve – is a darker shade. The baseplate, finished with perlage, is a comparatively lighter shade. In between this sea are the rose gold parts of the cam and wheels that govern the power reserve indicator. The indicator hand, with its star-tip, is also crafted from rose gold. The movement beats at a rapid 36,000 vibrations per hour.
Completing the picture is the blued alligator-style leather strap affixed by a blued titanium pin buckle. The watch comes with its set of outer and inner boxes, as well as its bill of sale and warranty paperwork from 2021. While the “Kind of Blue” represents an exceedingly attractive iteration of the award-winning DB28 aesthetic, the addition of De Bethune’s advanced tourbillon makes this rare reference all the more special.