What ichiboku-zukuri means
Ichiboku-zukuri is a technique of Japanese wooden sculpture in which the core of the head and body is carved from one block of timber. A statue is still called ichiboku-zukuri when its arms, the spread of its knees or its pedestal are made separately and joined on, provided the central mass is a single piece. Official commentaries usually pair the term with the species, as in single-block hinoki.
Carving from one log gives the figure the full volume of the wood. The heart of a thick log tends to split as it dries, however, so sculptors normally hollowed the interior from the back or the base to relieve that stress. The technique is characteristic of the early Heian period, and heavy, full-bodied figures with deeply cut drapery are regarded as typical of single-block statues of that time.
Two neighbouring terms need to be kept apart. Yosegi-zukuri builds the head and body from several blocks from the outset and suits large statues. Warihagi-zukuri takes a figure carved from one block, splits it front and back or side to side, hollows it and joins it again; because it starts from a single piece it is treated as an extension of the single-block method and is sometimes called ichiboku warihagi-zukuri. Commentaries do not always draw these lines in the same place, so an article is safest when it repeats the term the commentary uses.
Reading the records and the statues
Agency commentaries name the wood and the technique together. A seated Dainichi now owned by Arida City in Wakayama is described as a single block of hinoki, and an ink inscription inside dates it to 1062. The commentary on the seated Yakushi at Ninnaji explains that the body was carved from one block and hollowed from the base up into the torso and behind the knees. That small image is carved from sandalwood and left unpainted, a sandalwood image in the tradition of carving small figures from fragrant wood in one piece.
The difference from split-and-rejoined work shows in the wording. The commentary on the five wisdom Buddhas at Kongoji says that the head and body of Dainichi and others were carved from one block and then split front and back along a line behind the ears. When a text says one block and split, the statue is warihagi; when it says two blocks and joined-block construction, it is yosegi; when it says only single-block, the core was carved without being split.
On statues whose lacquer gilding or paint has gone, the grain of the wood can sometimes be followed. Grain that runs unbroken from head to foot suggests a single block, but visual judgement has limits and a conservation report is the reliable source.
References
- 木造大日如来坐像（有田市）｜国指定文化財等データベース（文化庁）
- https://kunishitei.bunka.go.jp/bsys/maindetails/201/4931
- 木造薬師如来坐像〈円勢、長円作／（北院旧本尊）〉｜国指定文化財等データベース（文化庁）
- https://kunishitei.bunka.go.jp/bsys/maindetails/201/124
- 木造五智如来坐像（五仏堂安置）｜文化遺産オンライン
- https://online.bunka.go.jp/heritages/detail/199066
- 金色堂堂内諸像及天蓋｜文化遺産オンライン
- https://online.bunka.go.jp/heritages/detail/207580
Last verified: 2026.09.26