Industrial Printing Process Queries, ZQA

Fountain Solution: Why pH and Conductivity Matter

What is the main goal of Fountain Solution in offset printing, and which parameters must be controlled?

Fountain Solution is a critical liquid in offset lithography, whose main goal is to moisten the non-image areas (non-halftone or non-dot areas) on the printing plate. This action prevents these areas from accepting ink, thus maintaining the essential water-ink balance. This solution constitutes the core of the offset press's Dampening System. Press supervisors continuously measure the solution's pH (typically between 4.5 and 5.5) and conductivity. Precise control of these parameters allows the press to operate with the minimum amount of water necessary, which in turn increases the ink drying speed and improves production efficiency and process stability.

Aligned with: ISO 12647-2 (Offset) / G7 / Press Chemistry Standards