Specification

Bark pockets are openings surrounded by bark on a veneer surface, usually
associated with a loose or cracked knot. They may have an elliptical shape
like those in the photos shown here, or they may have a more rounded
shape, depending on the angle of cut.
A burl is a cross section of an
abnormal growth that occurs on the
side of a tree. It may be a cluster of
pin knots from adventitious limbs that
develop when a limb dies off, or it
may be from an injury to a tree. It may
occur over a large area, or in a small
area as shown here. Burls are limited
in the higher grades in the standard.
The dark part in the center of the
cross section of a log is referred to
as heartwood. The lighter part that
surrounds the heartwood and forms
a band of lighter color wood all the
way out to the inner bark of the tree
is referred to as sapwood.
HEARTWOOD
SAPWOOD
HEARTWOOD
SAPWOOD
Gum is a feature of cherry that does
not occur to any great extent in any
other domestic species. Gum is a
deposit of an amorphous material
that is thought to result from the tree
attempting to heal an injury. It is dark
red in color, and very soft compared
to surrounding wood.
Mineral streaks are generally blue-gray to black elongated discoloration on
the surface of solid lumber or decorative veneer that may be caused by any
number of events including injury, disease, growth conditions, nutrients, or
even genetics.
t Mineral streak in hard maple
caused by the presence of syrup
tap holes, clearly visible in the photo
below.
It is common for wood to have naturally occurring anomalies that will show in the wood once peeled or sliced. Many of
these natural characteristics add to the appeal of wood and can even enhance its value.
BARK POCKET (large) BARK POCKET (small) BURL GUM
MINERAL STREAK MINERAL STREAK
MINERAL STREAK
t This plywood ceiling of natural
Birch panels is a great example of
heartwood and sapwood together in a
veneer face.
14 columbiaforestproducts.com Hardwood Plywood Grading Guide 2015
NATURAL CHARACTERISTICS