As it's name states the amount of foam should be flat - so as little as possible (~1cm). Little foam and more espresso makes flat white the perfect drink for latte art and one is able to create a great contrast from the double espresso and lightly steamed milk.

Why is a flat white called a flat white?

The naming of the flat white likely comes from how Australians refer to their coffee drinks. A regular espresso is a “short black,” one made larger with the addition of hot water is a “long black” and one with added milk is a “flat white,” Symons writes.

What is special about a flat white?

A flat white is a more concentrated drink that will have a stronger taste of coffee than milk. It can also be stronger than a latte in terms of caffeine because of the use of two shots. A flat white combines the flavour and intensity of an espresso with the rich mouthfeel of a dairy-based drink.