The rose is the decorative metal plate that covers the “bore” or hole in the face of a door that accommodates the door knob or door lever latch.
Roses, or Rosettes, are typically 2-5/8″ round and are the shape of door hardware due to the round hole in the door it is meant to conceal.
However, some styles employ a more elaborate design, typically rectangular in shape and measuring 2-5/8″ wide by 7″ or 8″ in height. This style is known as a Backplate, though Emtek, a manufacturer of historical reproductions, calls them “Sideplates”. Due to their size, backplates offer many unique design elements that enhance the door knob or door lever appeal. Nostalgic Warehouse, a Denver manufacturer boasting true reproduction hardware, (right down to the skeleton key!), offers six different designs in the most popular finishes like satin nickel and oil rub bronze. They utilize separate spindle and knob design, just like your grandmother use to have, and will fit any modern door as well as old doors without the large 2-1/8″ face bore. The backplate is becoming so popular that many leading manufacturers are now offering them including Baldwin door knobs and Kwikset door knobs