Final answer:
Kwakwaka'wakw masks are characterized by bilateral symmetry, calligraphic lines, ovoid shapes, as well as S- and U-forms in the formline style, marking a distinctive artistic tradition used in ceremonies.
Step-by-step explanation:
The common features of the formline style in Kwakwaka'wakw masks include several distinctive elements. First among them is the bilateral symmetry, ensuring that the design is the same on both sides of the mask. Another key feature is the use of undulating, calligraphic lines that flow throughout the mask, creating a sense of movement and fluidity. The ovoid shape is a fundamental form in formline art, often serving as the basic structure for eyes or other facial features. Additionally, S- and U-forms are intricately used within the design to define more complex patterns and shapes. These elements come together to create the visually striking and highly stylized appearance characteristic of the Kwakwaka'wakw masks. Used in ceremonial contexts, these masks are part of a rich cultural tradition that connects the natural and supernatural worlds.