To help guide our customers in their furniture choices – and unveil the art of furniture-making — we are proud to offer a blog series on the topic of wood grain and figure. This is the second article in our series. To read the first article, “Furniture Know-How: What Are Grain & Figure,” please click here.
The way in which different species of trees present the appearance of their grain is perhaps the most defining feature of their figure. Because different species of plants have different types of cells — and because these cells are arranged in different ways from species to species — the resulting grain from a sawn piece of wood will appear differently depending on the tree from which it is cut from. Other features will be different as well, including the color, hardness and resistance to rot, which will affect the durability of your furniture. We will explore each of these features, and how they affect the final appearance of your furniture in this article.
The basic pigmentation of wood varies from species to species. Black Walnut, for example, has a distinctively dark color, while Sugar Maple is a light-colored wood. Also, in general, the portion of a tree that is used for the lumber in your furniture may also affect its color. Usually, the older, inner wood is darker and the younger, outer wood (near the bark) is lighter in color — although not every species holds to this paradigm.
Writing Desk with Walnut top by Dave Hurwitz
Sugar Maple Taffy Table by Dave Hurwitz
Patterns of color from pigment contribute to a pattern in the figure in only a few species. Most of the differences in figure based on the species of wood depends upon the type and distribution of the structures inside the plant, and the types of chemicals and minerals the plant transports and stores during the life and death of its cells, often called “extractives.”
Cell Type and Distribution
The appearance of the grain is the result of the kinds of cells within in a tree, how many cells, where they are located, and how large they are. For example, the tall and thin cells that form most of the tall and thin structure of a tree are layered to greater or lesser degree depending on the growing season a tree had in a given year. You could sometimes even look at your furniture once it’s finished and tell which years were better for growing in that tree’s life by how thick each ring is, similar to how it’s done on a cut stump.
Even-grained woods, like white pine, and our local maple trees, have the dark and light parts of their rings evenly spaced and sized. By contrast, uneven-grained woods like southern pine and oak, will have larger disparities in the light and dark pattern of their rings.
Oak Tansu by Pete Novick. Note the thick lighter colored wood and the much thinner, darker wood. Notice also that the drawer faces are cut from the same piece of wood, a mark of fine furniture
When the cellular structures of wood are visible to the naked eye, as in Red Oak, they are called open-grained, or course-textured. If these structures are not visible to the naked eye (in other words, you can generally only see the growth rings and knots if there are any), as with Cherry, the wood is called closed-grain, fine-grain, or fine-textured.
Red Oak detail. Notice the grain that runs the length of the picture from left to right as being different from the shorter and darker horizontal pores throughout the surface of the wood.
Close-up of a Cherry Table by Richard Bissell where you can see the grain, but not the pores
Open or closed grain woods are in a class of trees called hardwoods. Guild member David Hurwitz explains: “The word ‘hardwood’ refers to deciduous trees – trees with leaves, and “softwood” refers to conifers – evergreens. But there are hardwoods that are soft – basswood, butternut, balsa wood, etc; and softwoods that are hard – yew for example… But the hardwoods used in furniture-making are much harder compared with typical softwoods like pine or spruce.”
Softwoods like pine possess a simpler structure than do hardwoods, lacking the porous elements. As a result they have an even finer texture than closed grain hardwoods, but less variety.
Pine detail. Notice the lack of features
Hurwitz continues: “Some woods, like maple and oak, are very dense and very hard, while other woods like butternut, poplar and basswood, are much softer. In fact basswood is so soft that it can dent easily, and is, therefore, not typically used for making furniture, though I have seen it used for drawer bottoms and cabinet backs on antiques. Basswood is more typically used for carving (birds, sculpture, etc). “
All of these factors may play into the wood that goes into your furniture. Guild member George Sawyer notes that sometimes every component of his Windsor Chairs require a different species of wood to perfectly suit the job. He explains: “For the back components, we select wood species with open grain, such as ash or oak. In these types of wood, the layers of grain tend to separate and bend more easily. For chair seats, we choose a species that is easy to carve, that is soft and light weight: pine, basswood, or butternut. Legs and stretchers demand a certain amount of stiffness and durability, as they’re bearing most of the weight and are abused in everyday use. The turnings can also have a considerable amount of detail, for which a wood with tighter grain is more suitable; sugar maple is ideal, and cherry a close second.”
Windsor Chair by George Sawyer with visible grain detail
Most of a tree, and thus, most of what you see when you’re looking at a piece of wood are the long thin cells and the pores (in hardwoods). However, there is more to the structure when you look deeper. Much like a human body, a tree has a sort of circulatory system in its outer layers. The long and tall cells carry fluids with dissolved chemicals and minerals up the tree, and the ray cells discussed in the first article in this series carry them outward. These additional substances are typically called extractives.
As the older, inner cells of a tree die and leave behind their tough cell walls to provide structure to the tree, the extractives become embedded in this remaining matrix. Because the extractives are different from species to species, their resulting effects also vary. The extractives can change the durability of your furniture, its color, the change in color as the furniture ages, and its resistance to rot.