To ensure the stability of the cushion, the underside of the zabuton cushion is flat. The top side of the zabuton is filled to create a dome-like shape, which is reminiscent of the shape of a Japanese fishcake called kamaboko. This shape not only provides extra fluffiness but also prevents the zabuton cushion from thinning too quickly, with frequent use. It takes a very skilled craftsman to achieve a plump and natural curve shape of the zabuton cushion.

The corner tassel stitches on a zabuton cushion are called “sumi-fusa”. It does not only function as a decoration, but it is also a traditional technique used to make sure that the cotton filling does not come out from the corners of the cushion. In ancient Japan, it is believed that putting tassels on the corners of the cushions prevents evil from possessing the user.