Authenticating Japanese Art and Collections

Japanese art has its own system of evidence. A signed wooden box, a seal impression, a later expert's inscription or a formal certificate can each support a piece, and each can also be misread or misused. This guide explains how Japanese collectors and dealers weigh that evidence, so that you can ask the right questions of any piece, including ours.

The box comes first

In Japan, the wooden storage box is part of the object's identity.

• Tomobako (共箱): the box made for the piece and inscribed by the artist, usually with the title on the lid and the signature and seal inside. For ceramics, tea utensils, scrolls and lacquer, a genuine tomobako can account for a large part of the value.
• Hakogaki (箱書): the inscription itself. It should agree with the object in subject, size and period.
• Kiwame-gaki (極書): an authentication written on a box by a later authority, such as the artist's heir, a successor generation of a kiln, or a tea master. It records an opinion; its weight depends on who wrote it.
• Awase-bako (合わせ箱): a box made later, or borrowed from another piece. It protects the object but proves nothing about it.

Boxes are copied and swapped too. A fresh box with an old object, or an old box that fits the piece loosely, is a reason to look harder.

Signatures and seals

Paintings, calligraphy and prints carry a signature and one or more seal impressions (rakkan). Collectors compare them with published references of an artist's seals across their career. Pay attention to the colour and texture of the seal paste, the crispness of the carving and whether the seal is printed rather than stamped. A seal that is perfect but sits on paper of the wrong age is a warning, not a reassurance.

Prints: original, later edition or reproduction

• Look for the woodblock's traces. Hand-printed woodblocks show slight variations of pigment, visible wood grain in flat areas and an embossed feel where the paper was pressed into the block. Photographic reproductions show a regular dot pattern under magnification.
• Read the margins. Edo-period prints often carry publisher's marks, censor's seals and date seals. Twentieth-century shin-hanga prints carry publisher's seals whose design changed over time, which helps date an impression.
• Understand restrikes. Some publishers reprinted from original blocks for decades. A later impression is genuine but worth less than an early one.

Read more in Ukiyo-e: Japanese Woodblock Prints and the Floating World.

Certificates and papers

• Modern Japanese painters. The Tokyo Art Dealers Cooperative appraisal committee, based at the Tokyo Art Club, issues certificates (kanteisho) for a defined list of modern artists. For other artists, the recognised authority is often the artist's estate or foundation.
• Japanese swords. Papers from the Society for the Preservation of Japanese Art Swords (NBTHK) grade blades and fittings from Hozon upward.
• Contemporary editions. Prints and multiples are normally signed and numbered by hand. Keep the publisher's or gallery's documentation and invoice with the work.
• Watches. Several Swiss houses issue extracts from their archives. See our guide to buying a watch from Japan.

A certificate is only as strong as its issuer. A document from an unknown "institute" adds nothing.

Words that change the meaning

• Utsushi (写し): a respectful re-creation of a famous model, a long and honoured tradition in tea ceramics and lacquer. It is not a fake, but it is not the original either.
• Den (伝): "traditionally attributed to". An attribution, not a confirmation.
• School of, circle of, after: in English catalogues these describe followers and copies, not the named master.

Provenance

A documented history (invoices, exhibition labels, gallery stickers, publication in a catalogue, letters) supports everything above. Keep every piece of paper that comes with a work, and pass it on when the work changes hands.

Red flags

• A price far below the market for a named artist.
• Photographs of the front only, or none of the box, seal or reverse.
• A uniform, painted-on patina, or wear in places that are never handled.
• Printed "woodblocks", giclée reproductions described only as "prints".
• A story that cannot be checked.

Our commitment

Every piece we offer is examined in Japan before it is described, and our descriptions follow the catalogue conventions above: a maker named without qualification is a maker we guarantee. Under our authenticity guarantee, if such a piece is shown not to be authentic by a written opinion from a recognised authentication service or the maker itself, submitted within 30 days of delivery, we refund the full purchase price and the cost of returning it.