If you have colorful patterned china, plates, and platters, you may want to consider using a neutral or solid-colored background for the back of your china cabinet to avoid overwhelming the eye with too many patterns. Alternatively, you could use a subtle, textured wallpaper in a coordinating color to add interest without competing with the patterns on your dishes. Another option could be to use a mirror or reflective surface, which would not only add depth to the cabinet but also reflect the beauty of your dishes. Ultimately, the choice of what to put on the back of your china cabinet depends on your personal taste and the overall aesthetic of your home.