Why Does Ghosting Appear on the Back of the Printed Sheet?
Back-side ghosting is a faint repeated image on the back of the paper, and ink has not actually been printed there. It is mostly solvent or vehicle bleeding through when sheets are stacked, or uneven drying transferring the front image to the back. It differs from set-off: set-off has ink you can feel, while ghosting usually has no ink layer you can feel. First determine which side it is on, then decide whether to change sheet stacking or the ink roller.
Back-side ghosting is a faint repeated image on the back of the paper; the ink has not actually been printed there. It is mostly caused by solvent or binder penetrating through during stacking, or by uneven drying transferring the front image to the back. It differs from set-off: set-off can be felt as ink, while ghosting usually does not feel like a layer of ink. First determine which side it is on, then decide whether to change stacking or change the ink rollers.
First confirm which side it is on
Turn the paper over. If the faint shadow is only on the back and the corresponding position on the front is a normal solid or blank, the problem is stacking and penetration: if the sheets are stacked tightly and the mineral oil or solvent in the ink is still migrating, it will show a fainter image of the same shape on the back. Scrape it with a fingernail; no layer of color comes off, only the paper color has changed.
If the front also has a faint shadow of the same shape next to a large solid, that is mechanical ghosting: the ink roller was drained by the previous large solid and did not replenish before the next one. For this, change the position of the solid or the ink roller arrangement; changing spray powder will not help. If both sides have it at the same time, address the ink supply on the front first, and the penetration on the back will lessen along with it.
Do not use the same method for both sides
| What you confirm | Cause | Fix first |
|---|---|---|
| Only on the back, no ink scrapes off | Penetration, stacking | Reduce stack height, switch to ink or paper less prone to penetration |
| Color can be scraped off the back | Set-off | Handle according to drying and spray powder |
| Faint shadow also next to a solid on the front | Insufficient ink supply from the ink rollers | Change image/text layout or ink path; do not just flip the sheets |
Do these first this round
- Look at both the front and back, and use a fingernail to distinguish “ghosted through” from “rubbed on.”
- If it is only on the back, reduce the stack height first; after 20 minutes, pull out a new sheet and see whether it still develops.
- If the front also has it, stop wasting time with the back-side method; directly check the distance between the large solid and the area after it.
