Many woodworkers avoid chairmaking for the joinery, the angles, the special tools required or the materials (green, rived stock?). And when it comes to designing a chair, even experienced woodworkers are hesitant to give it a shot because they are afraid they will produce a buttocks-torture device instead of a comfortable chair.
Producing a comfortable chair is the combination of many factors, but all of them are easily controllable. In my short 13 years as an amateur chairmaker and designer, here are some of the design details that I think are overlooked.
Many first-time chairmakers carve the seat so deep you could bake a Bundt cake in it. I’ve seen saddles that are 1” deep and so dramatically shaped that they would look at home on a Klingon battle cruiser.
A little saddling (3/8” or so) is nice and it makes the seat appear to flow. But you can get away with little or no saddling and make a perfectly comfortable chair.
The trick – in my experience – is to design the chair so the front edge of the seat doesn’t bite into the sitter’s thighs. You can do this several ways.
No. 1: Shorten the legs a bit so the sitter’s feet rest flat on the floor and their thighs are just slightly above the front edge of the seat. Many shorter people hate factory chairs because the front edge of the seat restricts the blood flow after a few minutes.
Just like with a table, it’s easy to make it too high. But making it a little lower than typical has zero downsides.
No. 2: Take a jack plane and round off the front edge of the seat. You can also do this with a spokeshave – hollowing out two areas for the thighs. This five-minute operation creates the illusion of a saddle and increases the comfort.
The Back Legs
The least comfortable chairs I’ve sat in had a seat that was parallel to the floor. It makes the sitter feel like she is being pitched forward.
I like to have the seat drop 1” (at least) from the front edge of the seat to the back edge. I achieve this by cutting the back legs shorter. Cutting the back legs also has the benefit of angling the back of the chair backward, increasing the comfort.
Don’t over-do it. After removing 1-1/2”, it will start to feel weird. A good way to experiment with this is to prop up the front legs on a 1”-thick scrap and sit in the chair.
The Angle & Height of the Back
The backrest doesn’t have to be bored at a reclining angle. You can bore the backrest at 90° and use the fact that the back legs are shorter to make the chair comfortable. However, I do like to recline the back a few degrees back (once you get into chairmaking you’ll find that all the angles are as easy as 90°).
What I have found to be quite critical is the height of the crest rail or backrest. In general, lower seems to be better. Once you put something above the shoulder blades, the lumbar seems to suffer.
You can design a chair that has a high backrest, but I think it’s best to also have something below as well for the lumbar (think Jennie Alexander’s chair).
About the Chair Above
Roy Underhill made the chair in the photo at the top of this entry. It’s a reproduction of a chair we both saw at Stratford-upon-Avon last summer. To the eye, it looks uncomfortable. The seat is flat. The arms and seat height are lower than a typical modern chair. And the area created by the arms seems like a tight fit (it is for large people).
But the chair is remarkably comfortable. And, if you watch the current season of “The Woodwright’s Shop,” you’ll see how it’s dirt simple to build.
— Christopher Schwarz