Yet upon closer inspection, the H1 Full Gold asserts its difference: the hour capillary has now been filled with a black fluid. This new colour is not simply a different hue of an existing version. It has been developed from scratch in partnership with Preciflex, the company responsible for all HYT fluid developments. 

9 to 12 months of development

Whether blue, red, green or black, the starting point is always the same: the creation of a stable, coloured liquid that is unaffected by UV rays and includes properties (expansion and viscosity) that prevent it from adhering to the capillary and ensure it can hold a meniscus to separate it from the transparent fluid. Simple in theory, but incredibly complicated in practice. 

"We clearly have more experience than three years ago," emphasises Grégory Dourde, CEO of Preciflex, "but for each new colour, we have to start with a blank slate. The chemicals we require simply do not exist at this time. To create this black, we tested a dozen different chemical compositions, playing with subtle variations of atoms, molecules and ions. This meant a total of 9 to 12 months of pure fundamental research." 

However, the result — a deep, completely opaque black — is not without consequence. At night, it is not visible. "The other colours that we have used before now could reflect the slightest beam of light," explains Vincent Perriard. "But black absorbs everything. We therefore had to develop a new system for reading the time in the dark." 

HYT invents the "deducted" hour

For the very first time at HYT, the capillary of the H1 Full Gold rests on a trough hollowed into the case and entirely coated in Super-LumiNova (SLN). Consequently, when the light level starts to drop, the SLN comes into its own, bathing the capillary in green light from behind. 

As the black liquid does not allow this light to pass through, only the translucent part of the capillary not yet filled with black fluid will be illuminated. The conclusion: the hour is read by combining the time elapsed... and the remaining time. This is a first for HYT – and probably a first in watchmaking as a whole. 

Limited edition of 50 pieces.