Mabushi: Cocoon Supports
Once a silkworm is ready to spin a cocoon, it is transferred to a special structure called a mabushi. The Shimada mabushi is made from straw twisted into zigzagging bunches. The small openings between the straw encourage the silkworms to build their cocoons, the finished cocoons were easy to cut out of the mabushi. Shimada mabushi were cheap to make, but they had to be remade every year.
By the 1920s the Shimada mabushi had effectively been replaced by the easy-to-fold, easy-to-open kairyō mabushi. In the mid–1960s, these were replaced by the ingenious kaiten mabushi, literally “revolving mabushi.” The kaiten mabushi consist of a set of square cardboard frames containing over 100 tiny cubbies. Silkworms are attracted to the top when looking for a place to spin their cocoons, so as the cubbies at the top of the kaiten mabushi fill with cocoons, the added weight spins the structure around a central axis, moving open cubbies to the top. This type of mabushi is still commonly used today.