The Unsung Hero Behind Edo Kiriko's Color Expressions

The origins of Edo Glass trace back to the state-run 「工部省品川硝子製造所」 (Kobusho Shinagawa Glass Factory), established by the Ministry of Public Works in 1876. The factory faced significant management challenges and, after a series of changes including privatization, ceased operations within just a few years.

"Running a glass factory is a tough business. You need a large team of highly skilled artisans, the material costs are substantial, and the process is incredibly labor-intensive. On top of all that, the furnace has to stay lit 365 days a year."

However, this environment cultivated a new generation of talented artisans who then forged their own paths in the world of Edo Glass. Nakakin Glass was one such offshoot. Its founder, Kingo Nakamura, a master of glassblowing, devised the revolutionary "Pokan method," completely transforming the process of creating two-toned cased (kise) glass.

"Previously, two-toned glass was created using a European technique where clear and colored glass were blown separately, then reheated and fused together. Our founder devised a method to create both colors at once and layer them thinly. We call it the Pokan method, named after the 'pokan' sound the glass makes when it's released from the mold."

The process involves gathering colored glass from the furnace, blowing it into a thin layer, casing it with clear glass, and then blowing them together as one. The advent of the Pokan method not only made glass production more efficient but also enabled the creation of an even thinner layer of colored glass.

"The Pokan method allowed us to blow thin glass that beautifully showcases the delicate patterns of Edo Kiriko, such as Hana-kiriko (flower patterns), giving birth to a world of color in what was once a transparent-only craft. That's why our founder, Kingo Nakamura, is revered as the unsung hero of Edo Kiriko."

Carrying on the Legacy of Handwork

As the third-generation successor, Michiko took over the company alongside her younger brother, Representative Director Seigo Nakamura. She recalls loving glass from a young age and often playing in the factory.

"The artisans back then were a bit rougher around the edges than they are today, so I was constantly getting yelled at, 'Hey, that's dangerous!' I'd sneak into the cullet piles, which were all sorted by color, and go exploring in the processing area. I was just a kid who was fascinated by glass."

Having grown up watching her parents run the factory—with her mother supporting her artisan father—Michiko took over the family business at the age of 37. Until then, she had been living in a completely different world as a dog groomer. She found fulfillment in the hands-on work of caring for animals, but when the very survival of her family's factory was threatened, something inside her shifted.

"Someone has to do this. But could anyone else truly protect this historic factory?"

A peculiar sense of mission began to well up inside her. At the same time, her husband, Jun, who was then an office worker, was struck with a sudden inspiration. "I want to create things," he declared, and began his journey to become a glass artisan from scratch.

Becoming a glass artisan requires delicate skill and a minimum of 10 years of training. The challenge at Nakakin Glass is even greater, as they use a special type of glass that is harder—making it ideal for Edo Kiriko cutting—but also solidifies very quickly. This demands not only precision but also incredible speed.

"The casing process is incredibly laborious and difficult. But my husband persevered through his training. Now, as a master artisan, he and my brother manage the entire production floor themselves. His skill has been officially recognized, earning him the titles of Tokyo Traditional Craftsman and Tokyo Meister (Tokyo Master Technician)."

Passing the Allure of Beautiful Copper-Red to the Next Generation

Nakakin Glass is fiercely dedicated to the stunning colors of Edo Glass. The gold-cased glass produced using their proprietary 'Pokan' method is something other workshops can't replicate. The most challenging of all is the red hue known as 'Dō-aka,' or copper-red. They have faithfully preserved their uniquely developed deep, rich, and profound copper-red.

'Copper-red is practically a living creature,' they say.

Crafted by blending copper with ten different metals and minerals, this color has an extremely low success rate. It might discolor during heating or reveal an unexpected hue during cooling... If the timing is off by even a fraction of a second, the beautiful red instantly transforms into a murky blue.

'The material costs are high, and there's a lot of waste. Even so, we are driven to keep creating this deep, profound red.'

The countless records of failure in the experiment notebook left behind by the founder tell the story of this challenge. And yet, the sophisticated hue of copper-red is essential for Edo Kiriko. To share the allure of these colors, Nakakin Glass Co., Ltd. is also actively developing products for the next generation.

Born in 2013, the year Mt. Fuji was registered as a World Heritage Site, the '逆さ富士シリーズ' (Sakasa Fuji Series) is one such creation. These are *guinomi* (sake cups) made from two-layered colored glass, adorned with simple Kiriko cut patterns. Peer into it from directly above, and you'll see a firework pattern. Turn it upside down, and the shape of Mt. Fuji appears. It's a product that could only come from Nakakin Glass, a studio that has long mastered the art of Edo Glass colors.

'We've had customers from France come to buy them, and recently, they've become popular souvenirs on high-end tours for inbound travelers. They're getting a great reception from our international customers.'

The appeal of Nakakin Glass also lies in its 'serious adult playtime' using traditional techniques.

Take, for instance, 'edomae,' a product born from the Tokyo Teshigoto Project. On this beautiful copper-red glass, the pattern carved entirely with Kiriko techniques is, believe it or not, tuna (maguro). The lapis lazuli color represents gizzard shad (kohada), and a vibrant red is used for shrimp (ebi), showcasing a delightful sense of playfulness.

You might be surprised and ask, 'Why carve tuna on such beautiful copper-red glass?' But this very humor is the essence of Edo's chic, or '*iki*.' By tackling what other Kiriko artisans won't, they breathe a sense of attachment into traditional crafts that can't help but make you smile.

Other examples include 'EDO AQUA GLASS,' which lets you grow hyacinth bulbs or cacti while enjoying rich color gradations, and '響奏' (Hibika), a glass speaker created in collaboration with patented sound-amplifying technology. In these projects, one can sense a spirit that echoes that of the founder, who was dedicated to developing new technologies.

'As artisans, we know some projects won't be profitable, but if we find something beautiful or interesting, we just have to make it. Work has to be fun, right? We face plenty of hardships, but feeling that excitement is what matters most.'

Glass Can Be Used for 100 Years. A Commitment to Zero-Waste Craftsmanship

Having long preserved the beauty of Edo Glass, Nakakin Glass is now taking on a new challenge: zero-waste craftsmanship. In glassblowing, the top portion, known as the 'kabura,' is typically discarded. Furthermore, cased glass, which involves layering colors, has long been considered difficult to recycle.

The '翠角彩 sui-kaku-sai' project, part of the Tokyo Teshigoto initiative, tackled this very issue. To maintain a consistent color ratio, they finely crushed the 'kabura' to develop a *masu* (square cup) glass in two new colors. The first, '' (light green), gets its color from 100% recycled components, while the second, '' (dark green), is made by adding color to the recycled glass.'This pale-colored glass is unique because it's made from recycled, mixed cased glass. When you pour sake into it, it sparkles with a mysterious allure. We've also added a sunken carving of a cherry blossom that becomes visible when filled with water.'Creating beautiful colors while being mindful of the environment. Nakakin Glass Co., Ltd. plans to continue taking on the challenge of creating products with recycled glass.'I'd love to try making recycled glass products where each piece has a unique color. By leveraging all the techniques we've honed over the years, I believe we can deliver beauty even through recycling.'They are also committed to passing on Edo Glass techniques to the younger generation to ensure their survival. An aspiring artisan who joined through an internship program is set to be hired next year. At the end of our interview, we asked, 'What do you think is needed to revitalize Japanese crafts?''All over the world, handmade craftsmanship is disappearing. To change that, I think we need to shift away from a lifestyle of mass production and disposability. I believe that living more mindfully—like eating from proper dishes instead of disposable ones—can change the way we see and value objects.'Edo Glass, crafted with painstaking care, can be used for over 100 years if it isn't broken. And so, at Nakakin Glass, the artisans continue their work, carefully hand-blowing beautifully colored Edo Glass every day.