Color measurements according to three sections of wood

Abstract

The purpose of this study was to measure each color of three sections of wood with instruments, and to examine whether there were differences between each color of three sections. The total number of tree species measured was 60, with the same number of conifers and broadleaf trees. A test piece, which was a cube with one side of 34 mm, was prepared for each tree species. End grain, edge grain, bark side and pith side of each test piece were flattened by a hand planer. Then, lightness L* and hue/saturation (a*, b*) in the L*a*b* color space were measured with a spectrophotometer. The results showed that the end grain had a lower L* compared to the other planes. The end grain was reddish and yellowish because it had a large a* and small b*. When chroma C* and hue angle h in the L*C*h color space were calculated from a* and b*, the end grain had a small dullness with less vividness because C* was smaller than the other planes. L*, a*, b*, C* and h on the other planes excluding the end grain were almost equal for each plane. Furthermore, it was found that the plane whose lightness L* had the strongest correlation with the density of the test piece was the end grain. Therefore, the correlation diagrams between the density, average of annual ring width, and L*of the end grain of each test piece were shown.