05-14-2018

Seeing the Grain

Seeing the Grain

One of the things we love about working with solid wood is seeing the natural qualities of each specific tree the lumber comes from.

 

When Joshua was working in Japanese timber framing, the respect for the life of the tree was so attuned that the beams of the structure would be built to face up as the tree would have grown when living, with the inside of the tree facing the interior, the outside facing out.

 

Grain is the story of a tree’s life cycle, and depending on how the lumber is cut, we see that story mapped in different ways. Knowing a little bit about that map can add to the beauty of the wood. For us, thinking about the tree in seeing the grain adds to our appreciation of the furniture we make!

 

The layers of the tree that we experience in solid wood furniture are mostly the heartwood and the sapwood. Heartwood is made of older, dead cells at the center of the tree. As they age and transform from sapwood to heartwood, these cells create the skeletal strength and structure of the trunk. Sapwood is the younger, softer, lighter-in-color, living wood that stores and moves nourishment throughout the tree from roots to leaves.

Slab Sawing

In this image, you can see the bark, the cambium layer just below the bark, the pale sapwood, and the broad section of heartwood in the middle.

 

Many familiar woods are known for the look and color of their heartwood alone, with the sapwood layer making up only an inch or two of the outside of the trunk. These species include common domestic trees like oak, walnut and cherry to name a few. White woods like ash and maple will have relatively much broader bands of sapwood, and the sapwood is used for its lighter hue.

Annual growth rings are the most familiar aspect to wood grain. Growth rings are of course the concentric circles that distinguish each years’ cycle — with lighter wood growing in the spring and darker wood in the summer as growth slows towards dormancy in colder seasons. Tropical woods without seasonal dormancy won’t show these same kinds of growth rings, such as mahogany. Some tropical trees will have more than annual bursts of growth based on local patterns of wet and dry. Or certain tropical species, like teak, will still have definite coloration that displays annual wet and dry seasonality.
However the tree grows, milling a round log into flat cuts of lumber will reveal different qualities of the grain depending on how you slice it.

Stacked slab-sawn lumber

Slab Sawing cuts parallel through the center of the log from end to end. This sawing method is familiar from slab-tables, for example, and is desirable in live edge furniture.

Flat sawn – showing face grain with “cathedral” patterns cutting through the growth rings

Flat Sawing similarly cuts mostly parallel, but includes rift-sawn boards in the center, discarding the less stable heart of the tree. Flat sawing will show beautiful cathedral patterns in the wood, called flat grain or face grain. We use this lumber for broader surfaces in our furniture, like door panels, table tops and the seats of our chairs.

Quarter Sawn or Rift Sawn white oak

Quarter Sawing shows long straight lines of grain as it cuts lengthwise down the growth rings at approximately a right angle. This vertical grain we use in elements of the furniture that we want to emphasize length and linearity – like the legs of a chair, or the planks of our shelving. Medullary rays are also visible in quarter sawn – which move sap radially through the tree in ribbons of cells perpendicular to the growth rings.

Knowledge about wood grain is a deep subject, but we hope this is a tiny peak into the subject will add to your appreciation of the wood in your home and furniture!