Resin Veins

Resin veins in lumber are a natural feature of some species of trees, such as pine and fir. These veins are formed when the tree produces resin to protect itself against damage, such as insect infestation or disease.

Resin veins are typically visible as thin, dark lines that run parallel to the grain of the wood. They may appear as individual lines or as a network of interconnected lines throughout the wood.