Do in Leaves and Wood Among the Bobo and the Bwa
by Christopher D. Roy (1947-2019)
University of Iowa
Dwo is the major spiritual being through which communication between man and Wuro is possible and desirable in his role as the representative of men to their creator. Wuro is a God of action, whose creations are celebrated in the rapid swirling rotation of masks.
The Bobo produce masks in leaves, fibers, wood, and cloth. Each of these is used by one or more segments of Bobo society in a range of traditional contexts. The many types of masks are distinguished by the name of the leaves or fibers used, the colors of the fibers, or the shape of the head of the mask. Each of these masks is a manifestation of Dwo.
The earliest, original forms of Dwo are the most sacred and most highly respected. Masks made of the freshly gathered leaves of various sacred trees represent the original forms of Dwo first revealed by Wuro, which are called Kwele Dwo. Masks made of the colored fibers stripped from kenaf represent later, revealed forms of Dwo. Each of the different forms of Dwo requires a mask that personifies it, that recreates its personal characteristics.
The most typical leaf mask is birewa sowiye, a mask that appears at the beginning of the performance season to sweep all impurities from the community. The head is made of the leaves of the saxada (Guiera senegalensis) and of the nere. The leaves of the West African mahogany form the body, and saxada leaves again form the arms.
Masks made of fibers are more sculptural than masks of leaves, for the fibers are more supple and durable, and can be manipulated using basketry techniques into more elaborate and identifiable forms.  The most ancient and important of these fiber masks are called kele. The body of the performer is hidden by a thick fiber costume knotted to a net foundation.
The most important types of wooden masks are sacred masks (molo and nwenke), escort masks (nyanga), and entertainment masks (bole). The sacred masks are representative, rather than representational masks, and do not represent any living, tangible being, human or animal.
Other masks, nyanga for example, are fairly naturalistic depictions. In the case of entertainment masks, the imagination of the artist is free to create innovative forms.
 When I distinguish between leaf and fiber masks I refer to the materials of which the body of the performer is covered. No leaf masks have wooden heads. There are fiber masks, however, that are entirely of the fibers of the kenaf and other fiber masks that have heads of wood and these wooden "heads of the masks" are the Bobo sculpture we see in museums.