Production Of Gold Bars, Ögussa GmbH Factory, Vienna, Austria

The standard gold bar held as gold reserves by central banks and traded among bullion dealers is the 400-troy-ounce (12.4 kg or 438.9 ounces) Good Delivery gold bar.
The kilobar, which is to say 1000 grams in mass, is the bar that is more manageable and is used extensively for trading and investment. The premium on these bars when traded is very low over the spot value of the gold making it ideal for small transfers between banks and traders. Most kilobars are flat, although some investors, particularly in Europe, prefer the brick shape.