In the early days luminous watch dials were used due to a very practical reason – soldiers needed to know time even at night. However, luminescence that we know today is far from the one used in the past.
First luminous material (radium) used in watches was radioactive and dangerous. Best example of this is inventor of luminous paint formula Dr. Sabin Arnold von Sochocky – he died in 1928 from poisoning of radium dial paint.
However, it is worth mentioning that the watches were safe for the wearer. They were only dangerous for workers in factory. But realization of the potential danger forced watch industry to look for a better solution.
By 1960s the situation has improved as the amount of radium in wristwatches was around 100 times less than in 1920s. This didn’t save radium from its ultimate demise - in 1968 radium was banned. That meant that something had to replace it. Tritium became a new king.
However, it also had major flaws: tritium was also radioactive and its half-life was only 12 years. Half-life shows how fast radioactive material decays. So after 12 years there’s only half of the tritium left. Naturally, this affected quality of luminescence. So an even better solution was needed.
Only in 1990s a solution that we know today became popular in watch industry. It was phosphorescent material strontium aluminate. These pigments are completely safe and offer other advantages – they do not decay over time and have different hues.
Of course, this solution is not perfect. Before using your watch in darkness, you have to “charge” it with light. Both sunlight and artificial light works. That’s not all! Even though a watch dial should glow for hours, usually it loses majority of its brightness in the first 30 minutes. It’s not uncommon that after few hours your watch may look completely dark. In reality it’s still glowing, just your eyes are not able to catch it.
Swiss Super-LumiNova is a solution that is used today by most luxury watch brands. Its history starts in 1993 when LumiNova was invented by Japanese company Nemoto & Co., Ltd. How is it then that Super-LumiNova is branded as Swiss? It’s because Nemoto & Co., Ltd. joined forces with a Swiss company RC TRITEC Ltd.
But why Swiss Super-LumiNova? According to the company, this material offers highest possible afterglow performance. It also is non-radioactive, REACH compatible, highly temperature resistant and resistant to environmental influences.
Sounds much better than being poisoned by radioactive radium, doesn’t it?..
Swiss Super-LumiNova is available in different colors. Eight to be exact.
- BL (Blue Line, emission at 485 nm)
- GL (Green Line, emission at 515 nm)
- VL (Violet Line, emission at 440 nm)
- WL (White Line, complete white emission)
- YL (Yellow Line, yellow emission)
- OL (Orange Line, orange emission)
- PL (Pink Line, pink emission)
- UL (Ultramarine Line, ultramarine blue emission)
What’s interesting, there’s a science behind colors. If you are in a bright sunlight and all of a sudden find yourself in a dark room, your eyes will be most sensitive to green color. However, after your eyes adapt, you become more receptive to blue color. That’s the reason why most of the watches glow in these two colors.
Other colors are not that popular but they allow manufacturers to come up with beautiful watch designs.
Our mission at SGS is to deliver quality without compromises. There’s just one “but”… It also has to be done for more than reasonable price. In this case we also couldn’t sacrifice Swiss Super-LumiNova for inferior alternative. But the same time we managed to keep the price low compared to luxury brands.
So in every “Eagle” that comes out of the factory you’ll find this top-notch Swiss luminosity solution.