Anisotropy
The property of wood exhibiting different physical properties (shrinkage, stiffness) along different axes.
The Dendrology Primer
A technical dictionary for architects, 3D artists, and woodworkers.
Bookmatching
A veneering technique where two adjoining leaves are opened like a book to create a mirrored grain pattern.
Burl
A deformed tree growth resulting in a highly chaotic, swirling grain pattern, prized for veneers.
Cambium
The thin layer of reproductive tissue between the bark and the wood that produces new growth.
Chatoyancy
The 'cat's eye' shimmer effect seen in woods like Koa.
Checking
Cracks that appear across the growth rings, usually resulting from rapid drying or stress.
Diffuse-Porous
Hardwoods where pores are distributed evenly throughout the growth ring (e.g., Maple), resulting in uniform texture.
Earlywood
The wood formed early in the growing season (spring), typically porous and lighter in color.
EMC
Equilibrium Moisture Content: The point at which wood neither gains nor loses moisture relative to the air.
End Grain
The surface exposed when wood is cut across the growth rings.
Figure
The pattern produced on the surface of wood by the arrangement of grain, rays, and color variation.
Heartwood
The dense, dead inner wood, usually darker and more durable.
Hygroscopic
The property of absorbing moisture from the air.
Interlocked Grain
Grain that spirals around the axis, reversing direction in layers, often creating 'ribbon stripe' figure.
Janka Hardness
Measurement of wood's resistance to denting.
Knot
A portion of a branch embedded in the wood of the tree trunk, creating a circular grain deviation.
Latewood
The wood formed later in the season (summer), typically denser and darker than earlywood.
Lignin
The organic polymer acting as the 'glue' binding fibers; its degradation causes wood to gray in sunlight.
Medullary Rays
Cellular structures radiating from the center, visible in Oak.
Oxidation
The chemical reaction with air/UV that causes wood color to deepen or change over time.
Plain Sawn
Lumber cut tangent to the growth rings, producing the familiar 'cathedral' arch grain pattern.
Quarter Sawn
A cutting method producing straight grain and ray flecks.
Ray Fleck
Distinct shiny flakes seen on quarter-sawn Oak, caused by cutting parallel to medullary rays.
Rift Sawn
Lumber cut at a 30-60 degree angle to the rings, producing the straightest, most linear grain pattern.
Ring-Porous
Hardwoods with distinct zones of large pores in earlywood (e.g., Oak, Ash), creating a coarse texture.
Sapwood
The living, outer layers of the tree, usually paler.
Spalting
Coloration caused by fungi, creating unique black lines.
Specific Gravity
The ratio of the wood's density to water.
Tannins
Natural chemical compounds (high in Oak) that react with iron to cause black staining.
Wane
The presence of bark or the lack of wood on the edge or corner of a piece of lumber.