This is the second post of an ongoing series about wood. Understanding its nature, the way it moves and changes, and the implications for designers and builders. Check back every Wednesday for the next installment.
For a furniture designer interested in working with wood, it's important to first understand how it's cut into boards. Because the different ways that wood is cut can have a huge impact in how it behaves once it's integrated into your final design. This information may be covered at fine furniture schools, but we were surprised to learn that a lot of industrial design programs skip this crucial wood information altogether. This series is intended to arm you with some basic information to help plug those knowledge gaps.
In my first post of this series I described one of the most common cuts, the plainsawn, it's advantages and disadvantages. Now we'll look at quartersawn and briefly touch on riftsawn, and try to clear up the confusion between the two.Quartersawn vs. Riftsawn Terminology Issues
There are conflicting opinions--even in the woodworking community--between what constitutes "quartersawn" versus "riftsawn." You'll even see even professional companies interchanging the terms, with two different companies defining them in complete opposition to one another. To make it even more confusing, board-cutting processes referred to as "quarter sawing" can actually yield boards that are both quartersawn and what's called "riftsawn," which we'll get into later.
To clear it up, we spoke with Randy Johnson, a lifelong woodworker and the former Editor-in-Chief of American Woodworker magazine. "The way I was always taught is that quartersawn boards are the ones where the grain, or the tree rings if you will, are 90 degrees to the face of the board," Johnson explains. This is what's referred to as "radial grain."
The bottom line: When viewed from the end, a board that is truly quartersawn will have the grain running straight up and down, like this:
In the last post we saw that plainsawn is the most efficient way to cut up a log--so why bother with quartersawn? Because a long, long time ago, woodworkers discovered a unique property to quartersawn boards: They exhibit very little wood movement--the way that wood can shrink, swell, warp, twist, cup, or bend with changes in humidity--compared to plainsawn boards.
Needless to say, this stability is attractive. That's why in the old days, when resources were abundant, anyone working with wood always preferred to use quartersawn wood. If you look at antique furniture pieces online, even with a small, crappy Craigslist or eBay photo, you should be able to spot quartersawn oak a mile away by its distinctive look:
However, as part of nature's bargain, quartersawn is not only the most stable and desireable--it's also the least efficient to produce, yielding the most waste. As you can see from the photo below large triangles between each board are discarded to make this cut.
That inefficiency means quartersawn is the most expensive type of board to produce. Will you want to use it in your designs? Yes. Will you pay more for it? Yes again.
With quartersawn wood, the cuts are made perpendicular to the tree's growth rings which creates a straight grain pattern that is much more uniform. The result is a board face that is more refined and might be suitable for cabinets or floors, or in any situation where the designer wants a uniform pattern. For instance, quartersawn will yield nice-looking table legs because all four legs will look the same (assuming you designers have taken the time to properly orient them!).
Quartersawn is also useful in pieces where there is something you want to highlight, instead of detract attention from. Among woodworkers, the look of quartersawn is considered a desireable aesthetic due to their radial pattern of so-called Medullary rays, which produce an attractive wavy pattern also known as "ray fleck." You can see such patterns here:
Compare that to the more decorative cathedral patterns of plainsawn boards.
As mentioned earlier, a distinct advantage to using quartersawn boards is how the cut wood will handle one of its biggest enemies: moisture changes. Quartersawn boards tend to warp and expand the least, and I will explain why this happens in a future post on wood movement. So for things that cannot tolerate much movement, like floors, quartersawn is preferred. Some quartersawn flooring is shown below.
Quartersawn is also the preferred cut for most string instruments. Many high-end acoustic and electric guitar necks and fret boards are made from quartersawn wood. The major advantage of this cut is that it can produce extremely thin pieces of wood that do not warp or twist. This kind of stability is required to preserve consistent sound through the lifetime of the instrument. Looking at the figure and the Medullary rays that you learned about above, you should be able to identify the guitars in the photos below as having been made from quartersawn wood:
Lastly, because of its look, quartersawn is often the preferred cut for those looking to design and construct high-end furniture or paneling.
In the next entry in this series, we'll take a look at riftsawn, and show you a handy video that will clear up the confusion between quartersawn and riftsawn.