Next, zinc dividers are cemented to the slab, creating a grid of 3-foot squares. To stop wet terrazzo from flowing into the parts of the slab where walls will be built, plywood strips are temporarily fastened to the perimeter. Right before the pour, the entire surface gets a thin coat of an epoxy solution. With the slab prepared, the terrazzo ingredients are combined according to a precise recipe: in this case, a quarter-pound of black pigment for every 94-pound bag of white portland cement and 200 pounds of marble chips. The chips are a mix of three colors: Cardiff green (70 percent), raven black (25 percent) and Georgia white (5 percent).