The Eichi II is renowned as a masterpiece of simple watches. Its intricate movement has been praised time and time again in this magazine. However, the reason this watch exudes such an extraordinary presence is not limited to its internal components. The lapis lazuli ceramic dial, which was created through trial and error, and the case that displays the movement are major elements that make the Eichi II a masterpiece.
First released in 2014. While retaining the excellent movement and ceramic dial that characterize the original Eichi, this model has been further refined. Also, starting in 21, cold forging was added to the case manufacturing process, resulting in a more refined case surface. The model in the center is a lapis lazuli blue dial model, added in 18 to commemorate Seiko's 140th anniversary. Manual-wound Spring Drive (Cal. 7R14). 41 jewels. Power reserve of approximately 60 hours. Diameter 39mm, thickness 10.3mm. Water resistant to 30m. (Right, center) Platinum. 715 million yen (tax included). (Left) 18KPG. 550 million yen (tax included).
Interview and text by Masayuki Hirota (Chronos-Japan)
Edited by Yuto Hosoda (Chronos-Japan)
[Article published in the July 2023 issue of Kronos Japan]
The pinnacle of technology brought together by Micro Artist Studio
Credor's Eichi II is now coveted by many watch enthusiasts. The reason for this is not limited to its exquisitely crafted movement. The unique texture of the case and the rich, lustrous ceramic dial set this watch apart from other luxury watches.
New to the Eichi II lineup in 2021 is a model with a lapis lazuli dial. Lapis lazuli, or lapis lazuli, is a material that has been prized as a gemstone since ancient times. Seiko has recreated this color on a ceramic dial for the Eichi II. This is an undertaking unique to the Micro Artist Studio (MA Studio) at Seiko Epson's Shiojiri Plant, which produces dials in-house.
Let's take a look back at how things have progressed so far. The Eichi, released in 08, featured a ceramic dial made by Noritake. However, when developing the Eichi II, in order to in-house as many processes as possible, Tetsuo Oguchi, who is in charge of decoration at the MA workshop, acquired the know-how to make ceramic dials. He attended Noritake's painting classes and learned the painting techniques. The ceramic plate that forms the base of the dial was located in Nagano Prefecture, where the MA workshop is located, by exterior designer Noriaki Ozawa. After much trial and error, the Eichi II was completed, featuring an even more intricate ceramic dial.
Enamel and ceramic dials are the same in that they both have a glassy glaze applied to the surface. The only difference is the base. A metal-based dial is an enamel dial, while a ceramic-based dial is a ceramic dial. Metal-based enamel dials will deform when heated, but they are easier to attach to the movement and less likely to crack than ceramic dials. Ceramic dials, on the other hand, do not deform when heated and can withstand higher firing temperatures. However, they are more difficult to attach to the movement and are more susceptible to shocks. By searching for a supplier that produces high-strength industrial ceramics, Ozawa was able to ensure the ceramic dial of the Eichi II was sufficiently durable.
Ceramic dials are suited to firing at higher temperatures. The lapis lazuli dial, added in 21, is an attempt to make the most of this unique feature. It is still fired using a glassy glaze, just like previous models. However, the manufacturing process is very different.
There are two methods for applying color to ceramics. One is on-glaze, where a pigment (coloring matter) is layered on top of a glaze. The other is in-glaze, where the pigment (coloring matter) is dissolved into the glaze by firing. The indexes and logo on the dial of the Eichi watch use the former method. However, Oguchi, who worked on the dial of the Eichi II, said, "I wanted to try in-glaze, where the pigment is dissolved into the glaze." The paints that can be used for in-glaze are black or navy blue. Oguchi searched for the paint and began working on creating a ceramic dial using the in-glaze technique. The finished product was a lapis lazuli-colored dial.
Since 14, the white dials of the Eichi II have been delivered with a glaze placed on a ceramic base. The MA workshop fires the material to melt the glaze, then hand-paints the indices and other details to create the finished product. In contrast, the process of applying the glaze for the lapis lazuli dial is carried out at the MA workshop. The reason is that "suppliers cannot do this." The MA workshop takes extra time and effort to achieve the desired color.
The standard method for obtaining a blue glaze is to add cobalt or manganese. However, as the amount of material added increases and the color becomes darker, color unevenness becomes more likely to occur. Oguchi tried to create a prototype lapis lazuli blue dial using blue and black pigments, but still ended up with clumps of black pigment remaining. How could he eliminate the clumps and color unevenness? He began mixing the pigment and glaze and crushing it in a mortar and pestle, then straining the glaze through a mesh. By sifting it and leaving only the fine powder, no clumps of pigment remain and color unevenness is reduced.
There are two types of pigment used for the lapis lazuli dial. After repeated trial and error, Oguchi finally settled on a color that matches the blued screws used in the movement.
There is also a trick to the firing process. The firing temperature used for the inglaze technique is a whopping 1200°C. This is much higher than the firing temperature of around 800°C used for onglaze, which is used to paint the indexes and logos. Initially, firing was done at a lower temperature, but after around 30 trials, the current conditions were settled on. The firing temperature of around 1200°C is much higher than that of a normal enamel dial. The reason Oguchi was able to use the inglaze technique was precisely because the ceramic dial does not distort even at high temperatures.
Furthermore, if you look closely at a ceramic dial, which is fired with a glassy glaze, you will see that it bulges in the center and then gently slopes down towards the periphery. This is because the surface tension of the molten glassy glaze causes the center to bulge. This is the same for the white dial, but the lapis lazuli dial makes this "fluctuation" more clearly apparent. Additionally, the outer periphery, where the white base is slightly visible, gives the dial a subtle shade of light and shade. Of course, this was also intentional. "With the lapis lazuli dial, we made the outer periphery stand out. However, depending on the firing conditions, the glaze can become uneven and the roundness of the periphery can change. We decided on the firing time and temperature taking these factors into consideration."
The raised glaze on the dial of the Eichi II creates a unique texture. The reason it has a nuance not found in other companies' dials is because it is made of ceramic. As mentioned above, if an enamel dial is fired at approximately 1200°C, it will warp at the high temperature. To correct this, the dial can be hammered upon cooling to make it flat, but the raised glaze will be damaged. However, with ceramic, which never deforms, there is no need to correct the dial. This is why the Eichi II has succeeded in making the glaze rise like surface tension.
Once the glaze has been fixed to the ceramic at around 1200°C, the next step is polishing. By carefully polishing the glassy glaze that has risen due to surface tension, the thick dial that is characteristic of Eichi is completed. However, when you look at the dial of the Eichi, you can see absolutely no traces of polishing that are common on industrial enamel dials. In response to this, Oguchi says, "When the polishing methods used to polish white dials are used on lapis lazuli dials, the scratches made during polishing become more noticeable."
