Functional pottery is made for people to use and many potters feel that the pot isn’t complete until it’s physically used for its job. If it is to do its job totally, it should be efficient, easy to use, comfortable in the hands, and give pleasure to the user at the same time. One should consider how it’s to be used and what parts of the human anatomy will be in contact with it for optimum satisfaction. Judging by a large volume of pottery that one finds in the marketplace, a great number of potters and pottery manufacturers seldom consider the anatomy of the user when making their wares.
The human hand and head are the parts of the body that generally come in contact with utilitarian pottery, and testing how our bodies interact with these objects to find what may or may not be comfortable in use is very important. Just how does a cup or mug rim feel between the lips? How does a handle feel? How many fingers fit comfortably between the handle and the body of the object? How many fingers are needed to comfortably lift the object without any undue strain? Would the handle be better if it were curved in another way?
Mouths, Lips, and Noses
Lips are fleshy muscular tissue covered with a highly sensitive thin skin. They are particularly sensitive to objects being placed between them. The surface quality, thickness, curvature, and width of the object are all sensed very quickly, and an instant reaction of pleasure or displeasure is sent to the brain.
The shapes and sizes of mouths are infinitely variable, and consist of two lips, the upper one of which generally protrudes slightly more than the lower. The distance from the bottom of the upper lip to the bridge of the nose averages 3–3 inches (7.5–9 cm). In between, of course, comes the nose. The sizes and shapes of noses also vary infinitely. If the opening of the vessel is more or less than 3–3 inches, it may feel awkward in use. If it’s larger than this dimension, the rim will probably force the mouth into an uncomfortably wide shape, causing it to dribble. At the same time, it will probably touch the lower part of the forehead when the object is fully tilted for drinking. If the vessel is less than the above dimension, it may feel awkward to both the lips and nose at the same time.
Finding the Center of Gravity
Often handles are placed on pouring vessels in such a way that energy needed to use the object is two or three times what is necessary, and therefore puts excessive strain on the user’s wrist. The center of gravity of a pouring vessel can easily be found by making a thin cardboard profile cutout of the vessel complete with handle, draw a vertical line from the center of the base to the center of the top. Then take the cardboard form in your hand and tilt it so that there is a vertical line from the bottom left part of the base, through to the center top part of the handle. Draw this line. Where the two lines cross (point A) is the center of gravity and also the point of balance. The further the handle is from the center of gravity, the more awkward the object is to pour from. Conversely, the closer the handle can be to the center of gravity, the easier it will be to use.
For maximum efficiency in use, the placement of handle and spout are subject to the following simple law: Find the center of gravity, then draw a line from the center of the handle through the center of gravity to the extremity of the pot. The spout should be at right angles to this line for efficient leverage and, therefore, easy action.
Fingers, Hands, Wrists, Elbows, and Shoulders
The joints of the arm are pivot points, which come into action whenever an object is lifted or tilted. The shoulder and elbow basically work like ball and socket joints, with only a limited amount of flexibility. The wrist is like a universal joint and can go in a variety of directions. The knuckles are like small ball and socket joints, limited in movement by the web of skin between the fingers. The finger joints are like small hinges. The combination of differently engineered joints gives the arm a wonderfully complex range of possible movements.
If everybody conformed to a set pattern, and the width and length of fingers were constant, it would be easy to design objects which served the needs of all. It would also be very boring! Part of the great challenge of making pottery for use is to make things that can satisfy either the individual or the masses.
The way hands are used in the lifting and holding of objects varies from person to person, depending on the length and thickness of the fingers, the strength of both fingers and wrist, and, to some extent, the cultural background of the user. The finger is made of three parts, with two joints within its length from the knuckle. The thumb has two parts and one joint within its length. When the fingers or thumb are bent, the muscles on the inner part of the finger are compressed to half or less of their normal length.
In many fine-quality, generally industrially produced cups, the handle is made in such a way as to make it impossible to get a finger through, necessitating a pinching action between the forefinger and thumb, with the middle finger supporting beneath. Most potters usually make handles where at least one finger goes through the aperture between the handle and pot. The thickness of the thickest part of an average forefinger is approximately 1 inch. For a cup or mug to contain hot liquid and not burn the finger holding the handle, the space between the finger and the body of the pot need be no more than inch, or a total space of 1 inch, from the inside of the handle to the body of the vessel. Although this might change slightly depending on the shape of the object, it won’t change much.
An excessively large handle is likely to feel awkward in use, as there will probably be too much lateral movement to feel totally secure. The forefinger is used most often for picking up and holding cups and mugs. Since the finger is in a crooked or bent state, a handle that is excessively wide or thick will also feel awkward.
For objects larger than drinking vessels, the placement and spacing of handles is equally crucial, since it also concerns leverage. The human wrist is one of the more fragile parts of our anatomy, being made up of a number of interlocking moveable bones. The angles it operates at and the weights it carries make it quite vulnerable in use, and comparatively easy to damage. Pots, becoming excessively heavy with their contents, should be balanced so that they can be made as easy as possible to pick up or to pour from.
Note: A liter of water weighs 2 pounds, 2 ounces, or 1000 grams. An average pitcher with enough capacity to contain a liter of water will weigh about the same as the liquid. Their total combined weight will therefore be a minimum of 4 pounds, 4 ounces, or 2000 grams. If the handle of the pitcher juts out an excessive distance from the center of gravity, the apparent weight will be considerably more than the actual weight. This could cause a strain to the wrist and be very uncomfortable in use.
All of these things may seem excessively fastidious, but they’re questions which concern many pottery users. Any concern that a buyer may have is likely to be a legitimate one, and being aware to these concerns might help us to make better pots.
Points to Consider
1. Are the top rims and the edges of the handles sharp to the touch for either lips or fingers?
2. Is the curvature at the top of a drinking vessel suitable for drinking from? Does it curve in or out, or is it straight up?
3. Is the shape of the object suitable to be held or drunk from?
4. Does the handle have sufficient room for fingers to comfortably fit?
5. Does the handle fit the hand, or do the fingers have to conform to the handle?
6. Is it balanced?
7. Does the shape of the pot need handles to fulfill its intended use?
8. Does the sound or texture of the surface aggravate the user?
9. Does the object as designed get too hot to hold?
10. Could it work better and be more comfortable to use than it is?
Excerpted form Functional Pottery: Form and Aesthetic in Pots of Purpose by Robin Hopper, and available in the Ceramic Arts Daily Shop.