Plate corrosion/oxidation during stops
Medium severitySymptoms
Rust dots or shadows when restarting after a stop
Probable causes
- Wet plate left ungummed
- overly acidic solution
- humid environment
The Print Guy · 2026-10-05
Other problems in this category
Fountain solution · TPG-047
Biological contamination (algae/bacteria)
Foul smell, slime in tank and lines, clogged filters
Fountain solution · TPG-048
Excess isopropyl alcohol (IPA)
High consumption, strong smell, reduced ink gloss, cost and compliance issues
Fountain solution · TPG-049
Alcohol substitute poorly adjusted
After reducing IPA: tinting, uneven dampening, foam
Fountain solution · TPG-050
High circuit temperature
Unstable dampening, IPA evaporation, emulsification, bacteria
Fountain solution · TPG-052
Water streaks on the print
Light vertical bands or washed-out zones in solids
Fountain solution · TPG-044
pH out of range
Acidic (<4.5): drying inhibited, metallics damaged, plates attacked. High (>5.8): tinting, scumming