A while back, I mentioned a toy I made for drawing Japanese seals. So, what’s the deal with Japanese seals, anyway? Seals, called Inshō (印章), were used for means of authentication throughout Japanese history, in similar ways to how they were used elsewhere. They were generally made of stone, with a flat, generally square face where the seal is carved and a handle end that can be carved decoratively. Instead of being used with wax, Japanese seals, like seals in other East Asian countries, were used as stamps with ink to sign documents, from official proclamations and contracts to works of art.(en.wp:Seal (east Asia))

Seals could be applied in several different ways; in addition to just being stamped at the bottom of a document, the seal could be applied so that it was half on the top of a document and half on an entry in an official record book; this allows a document to be later authenticated against the official record, providing more assurance against forgery. (This is similar to the European practice of indenture.)(CJOD)

One of the things that makes seals interesting is that they generally use tensho or “seal script”, one of the oldest ways of writing kanji (Chinese-origin characters), dating to Qin-dynasty China.(en.wp:Seal script) Seal script changed very little over time and in many cases bears little resemblance to ordinary Japanese writing; for example, here’s a seal for “鳴蛍” (“fireflies sing”), where several radicals (kanji parts) are significantly different.

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While official seals were generally square and of a straightforward design, seals used by artists had much more variation, being in arbitrary shapes such as circles, ovals, or diamonds, and containing more creatively stylized seal script names or other designs. The parallels here with professional and artistic signatures need no discussion. Two variations of a jar-shaped artistic seal associated with Kanō Eitoku, a 16th century Japanese painter, are shown here.

Circled Kano SealUncircled Eitoku Seal(KE:299)

Seals are one of the most unchanging traditions in Japanese culture; while they did move from Imperial use to use by the nobility to use by samurai to, eventually, popular use, their form and function remained consistent through the ages. It’s fun to see a tradition stemming from ancient China still used to authenticate documents in Japan today.