Growth Ring Contrast Enhancement and the Differentiation of Sapwood and Heartwood Zones


  • K. C. Yang


Sapwood, heartwood, growth rings, differentiation


A simple technique for growth ring contrast enhancement and the differentiation of sapwood and heartwood zones is described. A dried wood specimen was smoothed and wetted before the image of the growth rings and the boundary between the sapwood and heartwood was copied with a paper copy machine. The high contrast image of the growth rings and the sapwood and heartwood boundary was attributed to the capillary phenomenon of various sizes of cell elements and the difference of permeability between the sapwood and heartwood. This technique can be used for most species, and is especially useful for those species with a narrow latewood zone and without color differentiation between the sapwood and heartwood. This method is very helpful for data interpretation with various comparative studies of wood properties.


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