Grain Matching
Definition
The physical comparison of growth-ring pattern and fibre direction at a fracture or cut surface to an adjacent piece of wood. Because growth rings are continuous within a single piece of timber, the pattern at a cut is unique and can be matched to its companion piece like a puzzle edge.
- Basis
- Growth-ring pattern and fibre direction continuity
- Compared surfaces
- Fracture or cut surface to adjacent piece
- Famous case use
- Lindbergh kidnapping ladder evidence
- Analogy
- Matches like two edges of a torn puzzle piece
Common questions
What made grain matching persuasive in the Lindbergh case?+
A rail from the homemade ladder was matched to a board missing from the suspect's attic floor: the growth-ring pattern lined up across the cut, and nail holes in the rail aligned with nail holes in the attic joist it had been cut from, tying the ladder directly to his residence.
Does grain matching work on any two pieces of the same wood species?+
No. It only works when the two pieces were physically continuous before separation, because the match relies on the unique, non-repeating pattern of that specific tree's rings and fibres at that specific cut, not on species or general wood type.
Related terms
- Crossgrain
- A condition in which the wood fibres run at an angle to the long axis of the piece. In Rail 16, Koehler...
- Plane Mark
- A surface trace left by a hand or machine plane, showing the arc of the blade stroke and any irregularities such as...
- Rail 16
- Koehler's designation for the left side rail of the bottom section of the Lindbergh ladder. The rail that was matched by grain,...
- Supply Chain Tracing
- In Koehler's investigation, the process of tracking the ladder lumber from the sawmill of origin through the distribution network to the retail...
- Tool-Mark Analysis (Wood)
- Examination of surface marks left by cutting, planing, or shaping tools to identify the tool type, size, and individual characteristics of the...