〜Broad-Leafed trees and Needle-Leafed Trees〜

　We can divide the wood that we use into two categories wood from broad-leaf trees and wood from needle-leafed trees.
Both trees like the matsu (pine) which have actual needle-shaped leaves and trees like the hinoki which have scale-shaped leaves are found among the approximately 800 different varieties of needle-leafed trees. enerally speaking, most of these trees are evergreens, although there are some trees like the kara-matsu which are deciduous (i.e. lose their leaves in winter).
　Broad-leafed trees refer to trees like kusunoki, keyaki, tochi, katsura, etc. which have flat, broad leaves. Like needle-leafed trees, both evergreen trees like tsubaki which have green leaves attached throughout the year and deciduous trees like keyaki or katsura whose leaves change colors, fall and leave the tree completely bare. It should be pointed out that in this case the term evergreen doesn`t actually mean that the leaves remain on the tree forever, simply that the leaves fall off the tree when new buds appear to replace them in spring. There are many more varieties of broad-leafed trees than needle-leafed trees--the exact number of species isn`t really known.

　Hinoki, himeko-matsu, hiba, onko, etc. are among the needle-leafed trees used for sculpture. However, due to the severe difference in hardness between "summer wood" and "winter wood" and the remarkable elasticity and length of their fibers, their wood is somewhat difficult to carve.
The age-ring patterns of their wood can be beautifully finished without paint or lacquer and is therefore very appropriate for japanese buddhist carvings.

The trees that I listed above are relatively easy to carve, but compared with the broad-leafed trees that follow, the blades of your woodcarving knives must be very sharp to finish a piece..
because using sandpaper to finish the surface of a piece leaves the fibers of the wood without breaking them leaving a rough, blurred surface, it is almost impossible to finish a piece properly with sandpaper.
Arranged In order of ease of carving, the needle-shaped trees mentioned above are himeko-matsu, hiba, onko and hinoki. The hardness and difference between the summer wood and winter wood of matsu, sugi, tsuga, bei-tsuga, momi, etc. makes them inappropriate for carving.

　On the other hand, the wood of broad-leafed trees has a consistent hardness. Varieties that are most often used are katsura, hou, shina, kusunoki, tochi, kiri, tsuge, byakudan, etc. There are also imported varieties such as lauan, etc.
The easiest to carve are shina, katsura and hou. Because Lauan and other imported materials often contain crystalized silicon which can quickly blunt your knives, please be careful.

---

Growth Rings

　The diagram to the left shows a cross-section of a tree.
Under the bark of the tree, there is a "formation layer" where the cells of the tree divide and the growth of the tree actually occurs. Every year, the inner side creates the cells which become the wood of the tree and the outer side produces the cells which become the bark of the tree. The bark of thh tree splits and cracks and never becomes very thick; the wood interior to the formation layer grows on top of the growth rings of previous years and the tree becomes thicker year after year.

なつめ "summer wood"

ひかげ shade(northern side)

ふゆめ "winter wood"

しん center (heartwood)

ひむけ sunlight (south side)

きのだんめんず Cross-Section of a Tree

　Because Japan experiences four disctinct seasons, the shape and density of the cells of this formation layer change throughout the year. Therefore the growth rings of each year can be seen. In spring and summer, there is vigorous growth producing large cells with thick membranes. In the fall, the growth of the tree slows down and teh formation layer produces smaller cells with thinner membranes. As winter approaches, the number of cells produced decreases and actually stops when winter arrives. Through these year-long changes, the growth rings become clearly visible.

　The wood of the tree that is relatively newly formed is called the shirata (Jap. 白太--the white, thick part). This part of the tree holds an extremely large quantity of water, but doesn`t yet contain much of the tree`s sap; when this part of the tree is dried, it shrinks, contracts, splits and also, depending on the tree, becomes stained or discolored. In contrast, the older, more colored part of the tree is called the akami (Jap.赤身--the red part). This wood of this part of the tree contains all of the original qualities of the tree. because of these differences in the rate of shrinkage and the danger of cracking and warping, great care must be taken when drying wood.

　The rings of the tree are distorted from the center of the tree and stretched out in the direction of abundant sunlight (the south) because the cells on this side grow larger and thicker, which can warp and twist the growth of the tree. In contrast, the north side, which receives poor sunlight, produces much thinner rings with tiny cells and is therefore soft and less prone to splitting. In addition, because the "character" of young trees is not definitely established, they are often very hard and warped. Ideally, you should carve an older tree (100+ years) or as old a tree as you can find.