The interlocking of animal fibers that constructs a piece of natural felt is an apt analogy for the fitting-together of topics in a Sponge event. Because of its conceptual and structural relationship with the project, along with the relative simplicity of the process, felting has been included as a hands-on component in Sponges since they began. Felt objects are also foremost among the material manifestations of the project and have taken the form of wool felt mittens, boots, sea-sponges and kitchen sponges.