Spacing is rather close by default. It acts excellently on headline – caption – title axis, where characters stay close but are still ‘breathing’. In case a very compact setting is preferred, Altis easily tolerates some negative tracking.
Increasing white space around the letters might become necessary in a body copy, as in any font. When justifying narrow columns of small sized text, Altis doesn’t need much of a negative margin. As a minimum letter space approximately -1% is sufficient, because spacing is inherently tight. Flexibility should be directed above zero, to say a desired value of around 1-2% and maximum 1-2% more.