Ghosting
Gas Ghosting/Chemical Ghosting
The transfer of a printed image from the front of one sheet to the back of another.
| Cause | Cure |
|---|---|
| Large solids printed on a back-up form | Print the heavy coverage form first, and light form on the back-up side |
| Large lifts | Run smaller lifts when backing up the sheets |
| The first side is not allowed sufficient time to dry | Allow sufficient time to dry, typically 24 hours |
| The drying of the ink on the second side is accelerated or retarded by fumes given off by the ink solvents on the first side | Wind sheets before printing back-up side
Keep lifts in sequence Keep lifts away from sources of excessive heat and cold |
Mechanical Ghosting
This includes ink starvation and repeat ghosting type issues. This type of ghosting always occurs on the same side of the sheet.
| Cause | Cure |
|---|---|
| Poor layout | Lay the job out too minimize ink saturation of solids |
| Ink starvation | Increase ink feed |
| Ink film too thin | Consult ink manufacturer |
| Ink too transparent | Use opaque inks instead of transparent inks for solid tints |
| Too much water | Lower water settings, adjust chemistry |
| Ink rollers wrong diameter | Measure and replace rollers, increase pitch on vibrator roller |
| Blanket too soft | Consult blanket manufacturer and replace with harder blanket |
