Emerging from the late 19th century, French butter dishes are vessels that use two parts to form an airtight seal to preserve butter without refrigeration. The two pieces fit together, the bottom larger vessel holds a small amount of water, and the top vessel holds butter and functions as the lid, sitting upside down in the set. While the bottom vessel holds the water, the water creates the air tight seal when the top portion is put together with the bottom portion. The butter does not require refrigeration and can be kept soft and spreadable. When using this dish to keep butter, one can fit up to 1 1/2 to 2 sticks of butter inside, with sizes varying slightly.