Organized by Ellen Ziegler, this rooftop drawing event lasted two hours, culminating in the photograph taken for the 2013 Microsoft Gigapixel ArtZoom project. The artists attached sidewalk chalk to bamboo poles, then turned in place on sheets of tar paper, drawing intersecting circles that eventually spread to the surface of the parking lot. This spontaneous drawing was not planned in advance; the process of interacting with each other was as important as the final product.

Named after the Venn diagram (intersecting circles that serve to define the overlap of sets of information), the Venn Sisters are three artists who influence and support each other: Nola Avienne, Julia Freeman and Ellen Ziegler. They are all members of SOIL Gallery in Seattle. They are ready for anything, anytime.