Koshu hand-carved seals

Koshu hand-carved seals Koshu tebori insho

One-of-a-kind signature seals
Elaborate creation by expertly skilled artisans


What is Koshu hand-carved seals ?

Koshu Tebori Insho refers to hand-engraved personal signature stamps produced in the Yamanashi Prefecture cities of Kofu and Fujiyoshida. Bringing together all of Yamanashi’s engravers, dealers, and material producers, this local industry is unlike that found in any other prefecture.
One of the special characteristics of Koshu Tebori Insho seals is the designation of their materials as tsuge (box tree) wood, water buffalo horn, or crystal. The crystal seals were developed through crystal-cutting technology unique to the Koshu region.
If the seal is made of tsuge wood or water buffalo horn, the artisan uses a kiteito blade to roughly carve the part of the seal for the characters in the owner’s name, with a finer hansashito blade applied to finish the lettering. For a crystal seal, the face is carved out by tapping a curved chisel blade before a blunt-bladed chisel completes the lettering through the same process. The face of the seal is smoothed with a whetstone, and the letters appear written as mirrored (reverse) images within this space.
Passing down the traditional tools and techniques is an important part of the Koshu seal-making process. The production of the engraving knives is also an inherited practice that allows for the full expression of a beautiful completed seal impression.


The history of Yamanashi’s Koshu Tebori Insho began with the exhumation of massive, high-quality crystals from the Ontake mountain range. In 1837, a crystal-processing factory was established in the Ontake area outside of Kofu. Several different processing technologies emerged, and the number of crystal artisans and dealers increased. Woodblock carving techniques progressed, and tsuge wood and water buffalo horn as well as crystal came into use as seal-making materials. The development of the signature seal industry can be seen in documents such as the 1854 Koshu Consumers’ Guide. These writings mentioned woodblock artists working in printing in Kofu City, while other publications ran orders for materials such the rare grass-infused crystal Gokujou Gusaire Rokkaku (“highest-quality hexagon with grass”) and water buffalo horn seal materials. The documents suggest that at this time there were already skilled artisans in business, with various kinds of seal materials in circulation.
The demand for signature stamps from the general public increased dramatically with the Grand Council of State Proclamation of 1873, and the market expanded through the travelling and mail-order sales special to Yamanashi Prefecture.

General Production Process

Where to Buy & More Information

Kaiterasu (Yamanashi Jibasangyo Center)

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