The teabowls we make are based loosely on the Japanese "chawan" form. Rather than try to delve in my meager knowledge of tea ceremony and the making/using of chawan, I will defer to a source of greater authority.
A chawan is a bowl used for preparing and drinking matcha (powdered green tea) in Japanese tea ceremonies. In Japan, "chawan" also is the standard term for bowls for rice. If it is necessary to distinguish between them, bowls for rice are called gohan chawan (usually pronounced gohan-jawan), while the ones for use in chanoyu are called matcha chawan (matcha-jawan). The handle-less cups used for drinking regular course steeped tea are generally referred to as yunomi (lit., cups for hot water), while the small porcelain cups used for fine-quality steeped green tea are often distinguished as senchawan. When the word chawan stands alone, it is normally prefixed with the honorific o-.
There are many types of chawan used in the tea ceremony, and the choice of their use depends upon many considerations.
In tea ceremony, chawan are classified according to their place of origin or manufacture, colour, shape, materials and other characteristics. More than one classification may apply to a given bowl.
Most chawan are bowl-shaped, but shapes vary widely. There are names for each general shape, within which there may be many variations. Common shapes include cylindrical, flat and round. Cylindrical bowls are called tsutsu-jawan, while shallow bowls are called hira-jawan.
Chawan are also classified according to the type of tea that will be served in them: bowls for "thin tea" are referred to as usuchawan, and those for and "thick tea", koichawan.
Considering the formalities and tradition of Japanese tea ceremony, it is nearly impossible for a westerner to fully appreciate the making of chawan/teabowls. Alas, when I started making pots, and saw my first teabowls in Ceramics Monthly, I was hooked. Most of the potters I have worked with or worked for, made teabowls. None of them would be mistaken for Japanese chawan, but they also would not be mistaken for a soup bowl or a mug. The irony is that in America, people use them for EVERYTHING.... soup, tea, hot chocolate, coffee.... you name it.
So, the teabowls we make can only loosely be defined as influenced by Japanese chawan. I try to make them with the intent that they will be held, carried, sipped from....all in hand. Suffice to say, when you pick one up, it sits in just such a way in your hands that it begs to be sipped from.
Those are my thoughts today on teabowls. Probably have a slightly different take on another day.
For some more ideas about chawan/teabowls and more images: