Kannyu is the fine crack pattern appearing in a glazed surface, produced by the difference in shrinkage between body and glaze. Technically it is a defect; in tea practice it is highly valued as keshiki.
What to look at
Crazing is found in many Japanese wares — Hagi, kohiki, Shino, Raku — and with long use tea seeps into the cracks and the appearance develops. The "seven transformations of Hagi" and the rain-leak appearance are prized examples.
In practice
It appears in describing age — a bowl with good crazing, crazing that has developed. This is the clearest single case of tea practice inverting a technical judgement: the same feature a ceramics manufacturer would reject is the reason a practitioner keeps the bowl for thirty years.
About this article
Edited by the operator of Chaen (a one-person operation) / Last updated:
Tea ceremony descriptions can vary by school and source. Where interpretations differ, this glossary avoids definitive claims and focuses on broadly shared understandings. If you notice an error, please let us know viaContact. To learn about our organization, seeAbout Chaen.
Try it with your hands
Raku — fire your own tea bowlShape the clay, glaze it, pull it from the kiln — then use it in IppukuTerm info
- Category
- Term
Related terms
- Chado (The Way of Tea)chado
The Japanese practice of preparing and serving powdered green tea, treated as a lifelong discipline rather than a beverage ritual.
- Wabiwabi
Finding sufficiency of mind within insufficiency and plainness; one of the root concepts of tea practice.
- Ichigo ichie (one time, one meeting)ichigo ichie
The principle that every gathering is unrepeatable, and should therefore be treated as if it will never occur again.
- Kuchi-zukuri (the rim)kuchi-zukuri
The treatment, flare, and thickness of a vessel's rim; for a bowl it decides how the tea drinks.
- Tatami-tsuki (the standing surface)tatami-tsuki
The part of a vessel touching the mats — the outer circumference of the foot, where wear accumulates.
- Hi-iro (fire colour)hi-iro
Reddish-brown colouring produced on unglazed ware by the flame during firing.
- Yohen (kiln effects)yohen
Appearance produced by chance in the kiln — flame movement, temperature, falling ash — beyond the maker's control.