In order to improve the operation of an ink fountain, particularly for web offset printing presses, an ink fountain assembly is disclosed which includes a fountain roller and a fountain blade assembly which is positioned in operatively associated relation to the fountain roller. The fountain blade assembly has a fountain base with a key supporting surface and aim has a plurality of ink keys on the key supporting surface of the fountain base to extend substantially along the length of the fountain roller in variably spaced confronting parallel relation to the fountain roller. With these features of construction, the ink fountain assembly includes an alignment system for maintaining each of the ink keys in parallel relation to the fountain roller and a drive system for controlled movement of each of the ink keys toward and away from the fountain roller.