Edo glass edo glass
Burnished to the finest finish, appreciating the chic of Edo
Refined craftsmen’s skills fill everybody’s heart with joy
Edo Glassware is crafted in the Edogawa, Sumida, and Koto Wards of modern-day Tokyo. Nowadays, Edo Glassware is also produced in some areas of Chiba Prefecture, but this craftwork has been recognized as a local industry of Tokyo. Edo Glassware is characterized by its manufacturing methods that still use the materials and traditional techniques passed down from the Edo period. People have long been delighted by the quality of craftsmanship and the comfortable feel of such exquisite handwork that are evident in every single piece; unlike mass-produced factory items, each Edo Glassware creation is truly unique. Such craftsmanship is much appreciated across the generations and also abroad; Edo Glassware makes an ideal souvenir or gift. In each production process, highly-skilled artisans use the traditional techniques that have been passed on to the present day. In addition, regular exhibitions to showcase Edo Glassware and craftsmen are held to carry on the traditions and present the latest creations to the wider public; in particular, exhibition prize winners earn much renown and prestige, all of which will contribute to their acknowledgement as traditional craftsmen of the very highest rank.
The history of glass manufacturing in Japan begins with the discovery of the oldest glasswork estimated to be of the Yayoi period (300 BC - 250 AD), although it must be noted the simpler manufacturing methods of those days differ from the present-day methods. In the Warring States period (1467-1568) glass items were rarities exchanged only among the very highest classes and it was not until the Edo period (1603-1868) that full-scale glass manufacture started. In this period, the town of Edo was already Japan’s largest consumer city with a population of about one million, and at the beginning of the 18th century, in Nihonbashi-Torishio Town, Kyubei Kagaya, an important figure in glass making history, manufactured glassware for the common people, such as mirrors and eyeglasses. In the Asakusa area, another key producer, Tomesaburo Kazusaya, was making ornamental hairpins, wind chimes, and kaleidoscopes, which enjoyed tremendous popularity among the residents of Edo.
The catalog of exhibits for Japan’s 1st National Industrial Exhibition in 1877 records the names of Kyubei Kagaya and his son Yasutaro Kumasaki. In 1879, the Tokyo Glass Producers Association – the predecessor of the present TOBU Glass Industry Co-operative Association of Japan – was founded. Traditional techniques have been passed down from generation to generation, and in 2014, Edo Glassware was designated as a traditional craft.
General Production Process
- 1. Molten Glass
The manufacturing of Edo Glassware was modernized in the Meiji period (1868-1912); however, the basic manufacturing techniques date back to the Edo period. The Shinagawa Glass Works, a government factory in Tokyo, adopted Western-style manufacturing technology that had been introduced in the early Meiji period, and this became the driving force for development. The raw materials of glass are mainly silica sand, soda ash, lime, potassium, lead oxide, and other additives. These materials have been used since the Edo period and are still used today, which confirms the traditional ways have been faithfully handed on.
Currently, furnaces burn fuel oil or gas and the raw materials are heated to about 1,400ºC when they melt to a thick malt syrup consistency.
- 2. Ready for Shaping
The production process of Edo Glassware is mostly carried out by hand and high-temperature control and timing are very important, requiring considerable skill to make such delicate glasswork. The garasu-dane molten glass is especially heavy and needs the cooperation of several artisans to carefully remove the crucible from the furnace.
- 3. Press Molding
Molten glass is spooled at the end of a blowpipe and poured into a female mold, and then a male plunger is used to shape the molten glass by pressing from both above and below.
- 4. Free-Blowing
Molten glass is spooled at the end of a blowpipe, which is rotated while blowing air by mouth to create a bubble, ready for shaping with tongs and other tools; the glass is kept malleable by periodically heating in the furnace. This process is repeated until the desired shape is formed, and the master artisan expresses their unique vision by playing with the design, subtlety, uniformity, and balance of the piece.
- 5. Stretching Soft glass is placed in a receptacle mold and stretched to shape from above by using a spatula. In this technique as well, a skilled craftsman’s intuition is tested to the limit.
- 6. Mold-Blowing
Glass is poured into a fixed external shape such as a wooden or metal mold to give shape to the piece. In mold-blowing, air is blown into the glass, but unlike free-blowing which allows the creation of a totally free form shape, a standardized shape can be created many times. A stand is attached to finish.
- 7. Annealing Kiln
The temperature of the glass just after shaping is very high, and if it is allowed to cool too quickly, the glass will crack and break. Glass has a temperature known as the annealing point, which is about 500ºC; around this temperature, strains are likely to occur as the glass cools, and to prevent cracking requires an annealing kiln. At first a temperature of 500ºC or so is held for a time and then the temperature is gradually lowered over a period of at least half a day until completely cool; this process makes the glass outstandingly durable.
- 8. Product Distribution
Finally items are polished, finished, and inspected before dispatching to department stores, directly managed stores, or individual customers. It is fascinating to think that such a wide range of different products like tableware, sake drinking sets, or flower vases, are all made from the same basic ingredients and blown or shaped to meet so many different daily needs. At present, some workshops have their own showroom annexes, allowing the general public to directly see, handle, and enjoy the products.