The trace of linear motion constitutes a surface, which occupies a certain position in space and has the properties of two-dimensional space, including plane and surface. The edge line of the surface determines the shape of the surface, such as square, circle, triangle, polygon and irregular free shape. Fang is steady and serious; The circle is full of changes, with a light rolling and full feeling; Triangle has strong excitement and insecurity; Free-form rules change rapidly and at will.

Clothing, as an intuitive image, first presents the outline features in people's field of vision, such as the tent shape in the 1950s, the wine glass shape in the 1960s, the inverted triangle in the 1970s and the rectangle in the 1980s. Therefore, the obvious feature of the evolution of popular styles is the change of contours, which are ultimately formed by the change of lines, and the information conveyed by different graphic symbols is very different. In the dynamic and static changes, these lines have reached harmony and unity, forming a beautiful form of clothing. Clothing will show different contours when it is stationary and moving in space. When the wearer rotates, the pendulum of the clothing will unfold, forming many free wave lines. It is in this dynamic and static change that thread endows clothing with infinite charm and exuberant vitality.

In the modeling design of clothing, each piece of clothing is often regarded as several large geometric surfaces, which are combined in proportion to form a large outline of clothing, and then small surfaces are divided into the large outline according to the needs of function and decoration.