Ornamental metals have purposes that enhance both visual aesthetics and building functions. In high-profile urban projects, from retrofits of landmarked buildings to new components of transportation infrastructure, steel and aluminum components allow dramatic gestures, novel geometries, optimization of the materials’ properties, and purposeful contrasts in texture and form. The practical complications of combining customized metal pieces with other materials, particularly on retrofit projects, call for an understanding of those properties and hands-on experience with the details of construction.