When shopping for plywood at the lumberyard, you’ll notice letters like A, B, C, and D stamped on the sheets. These grades indicate the quality of the wood veneer on each face, helping you choose the right material for your project.
How Plywood Grading Works
Plywood sheets have two faces—front and back. Each face receives its own grade letter, creating combinations like A-B, B-C, or C-D. The first letter represents the better face (usually the front), while the second indicates the back quality.
Understanding these grades saves money by ensuring you don’t overpay for premium faces that won’t be visible in your finished project.
Grade A: Cabinet and Furniture Quality
Grade A represents the highest quality veneer. This face features smooth, sanded surfaces with minimal defects. You might find small, tight knots or minor color variations, but no open knotholes, splits, or patches.
Best uses: Cabinet doors, furniture panels, and any visible surface requiring paint or stain. Grade A accepts finishes beautifully and requires minimal surface preparation.
Grade B: Paint-Grade Projects
Grade B veneer contains more character than Grade A. Expect tight knots, minor splits repaired with wood putty, and occasional color variations. The surface remains smooth but shows more natural defects.
Best uses: Painted projects where minor imperfections won’t show through. Cabinet interiors, shelving, and backing panels work well with B-grade faces. Light sanding prepares the surface for paint.
Grade C: Structural Applications
Grade C veneer includes knotholes up to 1-1/2 inches, splits, and discoloration. Manufacturers fill larger defects with football-shaped patches. The surface feels rougher and requires significant prep work for finishing.
Best uses: Structural sheathing, subflooring, and hidden surfaces. C-grade plywood costs less but demands more surface preparation if appearance matters. Consider this grade for shop jigs and fixtures.
Grade D: Utility and Sheathing
Grade D represents the lowest veneer quality. Large knotholes, splits, and defects appear throughout. This grade prioritizes structural integrity over appearance—expect rough surfaces unsuitable for finishing.
Best uses: Roof decking, wall sheathing, and applications where appearance doesn’t matter. D-grade provides strength at the lowest cost but requires complete covering or painting.
Common Grade Combinations
A-A: Premium plywood with both faces suitable for finishing. Use for cabinet doors, furniture, and projects where both sides remain visible. Highest cost.
A-B: One premium face, one paint-grade back. Ideal for cabinet cases where interiors receive less scrutiny than exteriors. Good balance of quality and cost.
B-C: Paint-grade front with structural back. Common for built-ins and shelving where only one side shows. Mid-range pricing.
C-D: Sheathing grade for construction. Both faces contain defects but provide structural strength. Lowest cost option.
Selecting the Right Grade
Match plywood grades to your project requirements. Overspending on A-A plywood for shop cabinets wastes money, while using C-D for furniture creates finishing headaches.
Consider these factors:
- Visibility: Will both faces show, or can you hide the lower grade?
- Finish type: Stain reveals defects; paint covers them
- Budget: Each grade step up increases cost 15-25%
- Prep time: Lower grades require more sanding and filling
Shopping Tips
Inspect plywood sheets before purchasing. Even within the same grade, quality varies between manufacturers and batches. Look for:
- Core construction (veneer vs MDF center)
- Void-free edges indicating quality construction
- Consistent thickness across the sheet
- Proper storage preventing moisture damage
Hardwood plywood (birch, oak, maple) uses the same grading system but typically costs more than softwood varieties. The grade letters remain consistent across species.
Storage and Handling
Store plywood flat to prevent warping. Stack sheets on level supports with weight distributed evenly. Cover stored plywood to protect surfaces from dust and moisture.
When cutting, place the better face down for circular saws, up for table saws. This positions the cleanest cut on the visible surface.
Understanding plywood grades helps you select appropriate materials for each project, balancing cost against appearance requirements. Choose A-grade for visible surfaces, B for painted work, and C-D for structural applications where looks don’t matter.
