What type of milk is traditionally used in making a macchiato?

A macchiato is traditionally made using espresso that is "stained" or "marked" with a small amount of foamed milk. This technique creates a balance between the strong flavor of the espresso and the creamy texture of the milk. The foamed milk is essential in a macchiato because it contributes to the drink’s characteristic texture and mouthfeel, while still allowing the rich, bold flavor of the espresso to shine through.

Using other types of milk, such as whole, skim, or condensed milk, does not align with the traditional preparation of a macchiato. Whole milk and skim milk, while they may be used in other coffee drinks, do not provide the same textural contrast or the specific presentation that foamed milk does in a macchiato. Condensed milk introduces a rich sweetness and density that changes the intended flavor profile of the drink, straying from the classic macchiato experience.