Mutual Materials WS0411818PTY 18" x 18" Vancouver Bay Architectural Slab Platinum. Mutual Materials Vancouver Bay architectural slabs are popular in modern commercial designs for pedestrian walkways, landscaping, and rooftop patios. Increasingly, these large format pavers come in three sizes (24″ x 24″, 18″ x 18″, and 12″ x 24″) and are becoming designed into modern contemporary backyard outdoor living projects as well. Manufactured of durable concrete, our Vancouver Bay architectural slabs have a shot blast finish providing soothing color options and an elegant appearance. These architectural slabs provide a modern contemporary, yet timeless, design element.