Wood Spalting vs Staining
Spalting is rotting wood caused by fungus but is much more defined than staining from fungus. Usually spalting follows the grain lines, rotting the softer early wood and tracing along the harder late wood making those dark "ink" lines commonly associated with spalted wood.
Staining is more amorphous in nature and usually much deeper running all the way through wood without defined edges. This can be due to a fungus but can also be the natural enzymes in the wood reacting to external catalysts like heat, moisture, oxygen or even the oils from your hand as you touch it.
Both produce some interesting effects that make beautiful lumber. But some staining can be really bothersome like we find in Holly where we want that bright white look and the gray stain ruins that very quickly. Other times the staining is temporary and it oxidizes away like the streaky color of freshly milled Teak or Walnut that mellows in the sun.
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