The common fitted Western-style kitchen, developed in the early 20th century, is typically an arrangement of assembled unit cabinetry covered with a more-or-less continuous countertop work surface. The "unfitted" kitchen design style exemplified by Johnny Grey may also include detached and/or varied countertop surfaces mounted on discrete base support structures. Primary considerations of material choice and conformation are durability, functionality, hygienics, appearance, and cost.