The roller nip is critical in offset printing, both trans- porting and processing the ink and fountain solution. Offset technology is unique in that its process components – ink and water – are mixed under pressure.
The ink stripe – indicating the visual imprint when two rollers are in contact – varies according to type and amount of ink as well as in terms of viscosity, tack and yield value.
Analyzing an ink stripe is not always easy or accurate, due to its indistinct edge. Pressmen sometimes estimate from the outside of the stripe, sometimes from the inside.