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Koshu-tokubetsu-kicho

甲種特別貴重

What is Koshu-tokubetsu-kicho (甲種特別貴重)?

First-class (kō-shu) grade within Tokubetsu Kicho, part of the pre-1982 NBTHK paper system; Western collectors call these 'blue papers'. Collectors generally regard them as more dependable than other Kicho-era papers, but they are no longer issued, they are not equivalent to current NBTHK papers, and this site treats them like other pre-1982 papers.

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Related Documentation Terms

Aoe-kiwame青江極

Authentication certificate for Aoe school blades; formal attribution to this Bitchu Province tradition.

Blue-papers

Colloquial Western term for Koshu Tokubetsu Kicho papers. Generally regarded by collectors as more dependable than other Kicho-era papers, but no longer issued and not equivalent to current NBTHK papers. See: koshu-tokubetsu-kicho.

Den伝

Attributed to; traditional attribution without certainty.

Furukiwame古極め

Old attribution; historical sword appraisal or authentication, often from earlier periods.

Gō号

Art name or pseudonym used by smiths and artists; also the name given to a celebrated sword (e.g. Heshikiri Hasebe).

Green-papers

Colloquial Western term for Tokubetsu Kicho papers (pre-1982), which were issued on green paper; sometimes used loosely for all pre-1982 NBTHK papers. Largely disavowed by the NBTHK today: treat a blade whose only papers are green papers as unpapered. Exception: low-value fittings, where a modern shinsa can cost more than it adds. See: tokubetsu-kicho.

Hakogaki箱書

Box inscription; writing on a storage box identifying the contents, often by a recognized authority, used as authentication.

Hon'ami本阿弥

The most prestigious family of sword appraisers, active from the Muromachi period through Edo. Their origami certificates remain highly valued.

Horyu保留

Deferred judgement; a status given by NBTHK shinsa when a blade cannot be definitively attributed or authenticated. The item is held for further study rather than being passed or rejected. Blades with horyu status may be resubmitted after additional research or restoration work.

Hōryō法量

Measurements; the dimensions section (nagasa, sori, widths and so on) of a sword's appraisal description or catalogue entry.

Hozon保存

Worthy of preservation; NBTHK certification indicating a blade meets standards for historical and artistic value.

Juyo重要

Important; NBTHK designation for blades and fittings of exceptional quality, the second-highest NBTHK rank, below only Tokubetsu Juyo.