Which term describes separations of wood fibers, through growth rings, parallel to the grain?

• A. Shakes
• B. Checks
• C. Knot
• D. Splits

Answer: (B)

The idea here is about small, lengthwise cracks that form as wood dries. When wood loses moisture, the outer layers shrink faster than the interior, creating tensile stresses along the grain. A crack that runs along the grain and cuts through the growth rings is called a check. These are typically shallow, surface-to-mid-depth cracks that appear along the length of the board, following the direction of the fibers.

Other terms describe different flaws: shakes are more severe cracks that run through larger portions of the piece, often across the grain or through the entire diameter; splits are long cracks that extend through the thickness or length of the board; knots are where branches were embedded in the tree. So the term that matches separations of wood fibers through growth rings, parallel to the grain, is checks.