Natural Characteristics I

Effects of Growth Ring

• Growth rings are distinctive due to the light and dark colors
• Lighter portion is usually grown in the spring, called “springwood”
• Darker portion is usually grown in the summer, called “summerwood”

• Wide Growth Ring
• Narrow Growth Ring

Burl Grain

• Also known as curly grain, burly grain, fiddleback, or figure wood
• Causes include knot location, damage to cambium layer of bark, and tree genetics
• Common in most wood types

• Hard Maple
• Red Oak
• Soft Maple

Tiger Stripe and Cross Fire

• Unique pattern common in Red and White Oak
• Also in Hard and Soft Maple
• Most often found along with burl grain

• Hard Maple
• Soft Maple

Bird’s Eye

• Small area where fibers form circular figures on the surface
• Common in Hard Maple
• Rare in other wood types

• Bird’s Eye Hard Maple

Knots

• Closed Knot. Flat face with no openings in the surface.
• Open Knot. May occur as a very small pin-sized hole to a large gaping hole.
• Unsound Knot. A portion of the wood will move readily. Also known as a loose knot.
• Sound Knot. Also known as a tight knot. Solid, with no portion moveable. As hard as surrounding wood with no signs of decay.
• Pin Knot. Small, sound, and tight.
• Knot Cluster. A grouping of usually small knots.

• Closed Knot
• Open Knot
• Unsound Knot
• Sound Knot
• Pin Knot
• Knot Cluster

Bird Peck

• Woodpecker produces a small hole, which is a starting point for brown to blackish mineral streak
• Most common in Hickory and Cherry

• Bird Peck in Hickory

Cat’s Paw

• Cluster of pin knots in the shape of a cat's paw
• Most common in Cherry

• Cat’s Paw in Cherry