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.
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.
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.
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
Ring porous woods such as red oak produce two-tiered growth rings consisting of
coarse textured, darker appearing early wood (springwood
and smooth textured, lighter colored late wood (summerwood
are typically isolated, tightly
compacted figure features typically resulting when an outside force such as a winding
vine compresses the normal growth pattern in that region of the tree.
results when certain types of
wood cells called parenchyma cells multiply to fill voids left in the cambium as
a result of insect larval activity.
is a traumatic failure of the bonds between adjacent growth
rings caused by an outside force such as strong wind, ice, even felling the tree,
appearing as a ruptured, feathered, or very rough texture on a veneer surface.
A pin knot
with a dark center up to 1/8"
in diameter (in most grades) is called a conspicuous pin knot, and is limited by
the product standard in grades "AA", "A", and "B".
Inconspicuous pin knots
have no dark center
and are not considered when determining the grade of a sheet of veneer, as long
as they do not interfere with the overall appearance of the face.
A solid knot
is a cross section of a limb
that was dead when the log was harvested, usually appearing as dark in color, likely
containing cracks and bark that are subject to falling away during manufacturing.
are permitted on #2 backs and
lower, and on "C" grade faces and lower, with some restrictions as outlined in the
A sound knot
usually results when a live
limb existed on the log. It will contain growth rings like a smaller version of
the tree itself. The knot material is, as the name suggests, sound, and will most
likely remain in place throughout the manufacturing process.
Figure is a general term used to describe any deviation from the normal growth of
the wood grain, known technically as wavy or curly grain. Figure is so common as
to occur in all species to the extent that wood completely lacking in figure is
the exception rather than the rule. Slicing or peeling veneer from a log with wavy
grain often creates distinctive figure patterns that reflect light differently from
the surrounding wood. Some of these patterns are common to the extent they bear
familiar colloquial names as shown here.
Tightly compacted, densely populated figure patterns are often called "fiddle
," and, as the name infers, it is commonly used in musical instruments.
Occasionally, the grain will be compressed into what may be referred to as a waterfall
Figure that is clearly visible but relatively isolated on a given veneer surface
is defined in the HP-1 ANSI Standard glossary as a cross
. Cross bar figure is permitted at some level in all face grades.
, also called "ray
" is not actually figure in the same sense as the other types shown
here, but rather a result of a radial cut veneer that parallels one or more rays
that naturally occur in all species. Here we see flake that is common in quarter
sliced red and white oak as the rays in these species are quite large in comparison
to other species.
Occasionally, for reasons not fully understood, conical indentations, will occur
within a developing growth ring in many species of hardwoods, most notably hard
maple (Acer saccharum
). The indentations
are repeated in successive growth rings in a nested fashion that, when the log in
which they occur are sliced or peeled as veneer, the resulting figure pattern displayed
on the veneer surface resembles, as the name infers,
NOTE: The American National Standard for
Hardwood and Decorative Plywood, ANSI/HPVA HP-1-Current Year is the voluntary product
standard to which most hardwood and decorative softwood plywood is manufactured
in North America. Throughout this publication, any use of the word "standard" is
a direct reference to this particular standard. Please see the introduction to the
section on the ANSI/HPVA HP-1-2009 Standard Grading Tables on page 22 for further