Bowl design is a very subjective thing so what pleases the eye of one may not for another. That being said, there are a few conventions that generally hold true and are at least a good starting point when coming up with a design that will suit your esthetic and practical objectives. Once you get comfortable with these rather pliable tenets, you will have also learned when and where to break them.
The flat, steep-sided bowl below on the right is a classic design usually employed by a novice turner. This may be because of a desire to maximize the volume of that $10 blank but more than likely I feel the project was started with no particular design in mind.
HERE ARE A FEW TOOLS TO HELP YOU WITH YOUR WOODTURNING DESIGN BEFORE YOU EVEN CHOOSE YOUR BLANK.
1. WHAT IS THE “RIGHT” CURVE?
One convention is that the curved line of a bowl is more appealing if it approximates a catenery curve. A catenery curve is formed if you hold a light chain by its ends and let it droop. Whether deep or shallow (slack or taut), the line formed is called a catenery curve. We seem to be drawn to that shape and one of the theories is that we see that shape everywhere around us: vines, ropes, power lines, gondola lifts, a simple gold chain around a lady’s neck. Along with that is another tenet that is, for the most part, true. If that curve appears to complete above, on or just below the support surface, the form will have a lighter appearance. The profile of the bowl on the left in the photo below is an example of that curve completing above the surface (assisted by the small foot — more about that later).