Wood 101

Hardness is measured with a dent test called the Janka test. A machine presses a small steel ball, a little smaller than a marble, into a board until half the ball has sunk in. The Janka number is how many pounds of push that took. A bigger number means a harder wood, and a harder wood gets fewer dents.

Think of pressing your thumb into fruit: a ripe banana gives way, an apple pushes back. Wood behaves the same way. On a harder wood, dropped keys, chair legs, pet claws and knife cuts leave smaller marks. Harder isn’t automatically better, though: very hard woods are tough on knives, and softer woods are perfectly good for things that don’t get knocked around, like boxes, picture frames and drawer linings.

Next to hardness and weight, five small bars show where each wood sits, from one bar (softest or lightest) to five bars (hardest or heaviest).

• Softest or lightest, like Spanish cedar
• In the middle, like hard maple
• Hardest or heaviest, like Macassar ebony

Dots rate shimmer the same way, from one to five. Dollar signs rate the cost of the wood, from $$$$$ to $$$$$.

Light and air slowly change the color of all wood. Most woods get darker or warmer, and cherry changes the most. A few get slightly lighter, like walnut. Bright woods like padauk and purpleheart slowly turn brown. It happens behind window glass too, for the same reason we get a suntan at the beach.

Cherry darkens

Black walnut gets lighter

Swatches are approximate, in a normally lit room.

Some woods seem to glow and move as you walk past them. This is called chatoyance. It’s a lot like the old holographic Pokémon cards that seemed to move when you tilted them back and forth. A lacquer finish shows shimmer at full strength; wax shows less of it.

• None, or very little (for example, hard maple)
• A nice natural sheen (for example, padauk)
• A soft glow that moves in the light (for example, cherry)
• Strong, eye-catching shimmer (for example, bubinga)
• Spectacular: the shimmer is the star (for example, sapele)

Some woods, like oak, ash and wenge, have tiny pores you can see and feel, which gives them more texture. Under lacquer, that texture can be left in for a natural feel or filled for a glass-smooth surface.

Wood doesn’t come with a “food-grade” stamp. A common rule of thumb is that if a tree yields edible food, its wood is food-safe too. That’s why maple, the tree that gives us maple syrup, is one of the most common food-safe woods. Walnut is a close second.

• Ideal for foodThe top choice for cutting boards and butcher blocks.
• Good for foodGood for cutting and serving boards.
• Serving pieces onlyTrays, bowls, handles and accent stripes, but not the main cutting surface.
• Not for foodKeep it away from anything that touches food.

None of these woods are known to be poisonous, but the ones marked not for food can cause severe allergies. Cutting boards, bowls and other pieces that touch food get a food-safe oil-and-wax finish, not lacquer. Lacquer is a plastic-like resin that keeps hardening over time, and it shouldn’t come in contact with food.

Each wood page suggests woods from this guide that look great with it, either as a strong contrast (light maple with dark walnut) or as a calm match (cherry with walnut). A few pages also list pairings to avoid, like red oak with white oak, whose pink and olive tones clash more as they age.

Weight tells you how solid and heavy a piece will feel. Cost gives a rough idea of what each wood costs per board foot. A board foot is a piece of wood 12 inches square and 1 inch thick.

Take the cost ratings with a grain of salt. I based them on what I’ve paid for each wood in the past, and wood prices move with global supply and demand. I once bought hard maple cheap, came back a year later, and paid three times as much because that year’s maple harvest wasn’t as good.

Wax and oil-and-wax finishes: wipe clean with a damp cloth and dry right away. Keep wood out of the dishwasher and don’t leave it soaking. When the surface starts to look dry or dull, rub in a fresh coat of wax.

Semi-gloss lacquer: wipe with a soft, damp cloth. Use coasters and trivets for drinks and hot dishes.

Any finish: wood keeps changing color in the light. On a new piece, move lamps and vases now and then so they don’t leave a pale ghost spot. New cherry is the most sensitive.