The assembly method for the spout and handle of a Teapot, in relation to the body, is basically handled in two ways: with a line of intersection and a transitional line. In purple clay craftsmanship, these two methods are referred to as “Exposed Joint” and “Concealed Joint.” Due to the hand-molding nature of purple clay, the connection between the spout and handle with the main body often adopts a transitional line structure. Jingdezhen porcelain Teapots, limited by the properties of their materials and forming processes, mostly use the line of intersection for the separate joining of the spout and handle to the main body, while the transitional line structure is less common.

The connection between the spout, handle, and lid of a Purple Clay Teapot can be either exposed or concealed. When there's a clear boundary between the spout and the body, it's called an “Exposed Joint”; when there isn't a clear boundary, it's referred to as a “Concealed Joint,” such as in the Han Bian teapot where the spout and the shoulder line of the body are seamlessly integrated, giving the shape a characteristic of being smooth and flowing.

An Exposed Joint refers to a clear boundary at the connection between the spout and handle and the body of the teapot.

As seen in the “Three-Foot Level Teapot,” the spout uses an exposed joint, with clean lines that enhance the distinctive features of the teapot's shape. The straight, slim, and upward-curving spout is elegant and upright, while the ear-shaped handle is well-proportioned, gracefully shaped, and comfortable to hold.

A Concealed Joint has no obvious boundary at the connection, appearing natural and seamlessly integrated with the body of the teapot.

The characteristics of using the concealed joint method (transitional line structure) are that the spout and handle blend naturally into the main body, creating a strong sense of unity. Purple clay artisans refer to this as “appearing as if naturally grown.” For example, the spout and handle of the Shibi teapot are treated with the concealed joint method, where the handle and spout extend from the shoulder line of the body, blending naturally and forming a unified shape. The bridge knob sits atop the flat lid, the straight spout, and the triangular handle have slightly rounded corners; the body is relatively full, the feet are round and plump, revealing a touch of softness and beauty.