If the ink dries too slowly in the stack, one can speak of a lag in drying time. This may lead to an ink rub-off of the print during print finishing or during transport. The interaction between ink, additives, and dampening solution is usually to blame for lags in drying time. For example, should the

pH-value of the dampening solution fall below 4.7, one can count on a longer drying time. Improperly dosed additives (drying accelerators), a stack temperature that is too low, or excessively emulsified ink also retards drying. In principle, the heavier the ink film, the slower the drying process.

Solution:

• Optimal tuning between ink and paper (inquire with the manufacturer)
• Do not allow the pH-value of the dampening solution to cross below 4.7
• Avoid ink emulsification
• Only dose additives according to the manufacturer’s indications
• In cases of lower ink taking, also print ink stripes
• Avoid high ink film densities (employ ink reduction or high pigment inks)
• Use IR drying
• In order to rescue a print job, coat it with an oil or dispersion varnish