Grading & Grain Orientation
Grading
To ensure consistency and quality, it’s classified into four distinct grades—B/BB, BB/BB, BB/CP, and CP/C—each reflecting the appearance and allowable defects on the face and back veneers. Understanding these grades helps buyers match the right panel to their project’s aesthetic and structural demands.
Grade B
Highest grade of Baltic Birch Plywood, permitting minimal splits and ruling out any need for repairs. B represents face and BB back veneer. The face veneers are characterized by clarity and a defect-free, light, uniform color. On the back side, allowance is made for 3-6 color-matched patches. The inner cores, comprising solid birch single-piece veneers, reinforce its structural integrity. Surface is sanded intended for natural finish. This grade is often used in applications where the plywood will be visible, and a cleaner and more refined appearance is desired.
Pin knot
Light knot
Loose knot
Pinhole
Burl
Light inbark
Dark inbark
Sound discoloration (congested streaks)
Swirly grain
Streak traces
Water stains
Close shakes
Knots with bark inclusions, knot holes
MR (interior glue) plywood over sanding
WBP (exterior glue) plywood oversanding
Delamination
Overlap
Patch
Waviness (sanded plywood), rough saw cut, ripple
Posted veneer chips
Metal inclusions
Bark patch
Coarse peeling
Shears (defects caused by cutting)
Grade BB
Second highest quality in Baltic Birch grade system. Both face and back sides allow color-matched patches, while knots and open defects are repaired with veneer inserts. The inner cores, comprising solid birch single-piece veneers, reinforce its structural integrity. Surface is sanded.
Pin knot
Swirly grain
Pinhole
Dark knot
Close shakes
Streak traces
Sander skips (uneven sanding)
Overlap ridges (telegraphing overlaps)
Patch
Double patch
Pockets (without bark inclusions)
Sound discoloration (false heartwood)
Hollow
Gum hollow
Knots with bark inclusions, knot holes
MR (interior glue) plywood oversanding
WBP (exterior glue) plywood oversanding
Posted veneer chips
Waviness (sanded plywood), rough saw cut, ripple
Metal inclusions
Delamination
Bark patch
Blister
Discoloration with partial wood damage
Grade C
Patches, open knots, and minor veneer splits are acceptable. Veneer lap and small core voids are allowed. This panel is intentionally unsanded, but with guaranteed strong gluing properties, this grade is ideal for various structural applications.
Dark inbark
Shake filling and sealing with inserts and putty
Shears (defects caused by cutting)
Dark knot with a shake
Gum hollow
MR (interior glue) plywood oversanding
WBP (exterior glue)
Overlap
Patch without color matching
Saw cut
Black knot
Dark intergrown knot
Bark patch
Blister
Delamination
Discoloration with partial wood damage
Grade CP
CP grade is excluded from BB classification due to minor defects and increased streaking. Permissible occasional hairline splits of less than 0.5mm. Oval or round patches may or may not match the color of the base face veneer. Typically, there will be more patches per face compared to the BB grade. Surface is sanded. Grade CP/CP is designed and ideal for laminating applications.
Wood discoloration during storage
Coarse peeling
Overlap ridges (telegraphing overlaps)
Shake filling and sealing with inserts and putty
Sound discoloration (false heartwood)
Adhesive thread occurrence
Glue stain
Gum hollow
Hollow
MR (interior glue) plywood oversanding
WBP (exterior glue) plywood oversanding
Double patch
Knots with bark inclusions, knot holes
Blister
Delamination
Bark patch
Discoloration with partial wood damage
Face Veneer Grain Direction
Long Grain
Long grain refers to the orientation of wood grain in plywood where the wood fibers run parallel to the length of the sheet, resulting in a smoother and more uniform appearance. It affects the plywood’s structural characteristics and flexibility.
Short (Cross) Grain
Cross grain refers to the orientation of wood grain in plywood where the wood fibers run perpendicular to the length of the sheet, contributing to increased stiffness and resistance to bending along the width of the plywood.
