In Part 1, we considered how grain is the most significant factor affecting lumber color, due to how light reflects off the wood, depending on its density. Grain and density can be affected by many factors, and it’s only the beginning: local climate and weathering come in after grain to provide a wide variety of coloring within each individual lumber species.
Environmental Influences on Grain
Density variations occur as grain flows around where branches once were as well as when greater stability was necessary to combat extreme wind or gravitational pull. Varying growth periods will also impact density, since more closely grouped growth rings will create greater density, and widely spread growth rings will create less density. Annual shifts in climate will mean that even within the same tree, changes in density will occur. Figured grain can also impact density, bringing with it surprising and beautiful curly and quilted designs. In such situations, even a change in your perspective can reveal dramatically different hues within the same board.
Industrial Influences on Grain
Not only does nature impact the density or grain of each board, but how it’s milled also impacts the resulting color. First, the part of the tree from which a board is sawn will make a difference: boards cut from near the center will look different from those cut from the outer edges of a log. If boards are Rift or Quartersawn, they will likely include Medullary Rays, or flecks of denser material, which combine with parallel grain to create a striped appearance or a uniformly darker board. If tearing occurs during planing (a problem often encountered with Quartersawn boards), color is further affected. Add to all of that, the fact that end grain appears darker than that of a board’s face.
Post-Milling Environmental Influences
After grain, environmental influences to which the board is subjected after being sawn can significantly impact a board’s coloring. Over time, direct exposure to sunlight will eventually cause any species to fade to a silvery gray hue. While that shift is gradual, many color shifts along the way lead to extra complications in matching color. Even if a board is part of the same pack as another board that started out the same color, the boards located on top may receive more sunlight and therefore fail to match other boards in the pack that were nearly identical when freshly milled. Chemical changes and moisture levels further impact each board. The good news is that this process doesn’t stop; over time, color differences will mellow, creating a better color match as time goes on.
In Part 3, we’ll explore a few more factors that can make a difference when it comes to lumber color and then — the part you’ve probably been waiting for — a few practical tips for getting the best color match possible.