If a printer produces sharp text in one direction but doubled edges in two-way mode, we recommend preserving that comparison before changing alignment values. It gives the technician a useful clue. It does not, on its own, identify a failed component or prove which correction is needed.
This article concerns carriage printers that support bidirectional printing. A single-pass print system does not make the same opposite-direction carriage comparison; confirm the installed architecture first.
A real operator question: why did one-way mode look fine?
A Signs101 discussion about a Roland VG-540 describes good unidirectional output but blurred bidirectional output. The operator had changed several alignment settings and was unsure how to interpret the targets. We take two questions from that account: was the baseline usable, and which settings had changed? The discussion is third-party experience, not a confirmed fault report for HANNAI equipment.
The useful response is a controlled comparison. Save the original preset and values before an authorized adjustment. If the machine supports equivalent one-way and two-way diagnostic tests, keep the material, loading, artwork and other supported job settings unchanged. Where the printer changes additional parameters with direction mode, note that limitation rather than claiming a perfectly isolated test.
Establish a readable baseline first
Print the approved nozzle check. Missing or deflected jets can make the alignment target hard to judge. Use the nozzle-check and cleaning guide to organize that evidence before selecting correction values.
Load the intended media using its documented preset and support arrangement. Epson’s alignment guidance identifies nozzle condition and the loaded media as prerequisites. Those principles help structure the investigation; they do not make an Epson procedure a calibration method for another manufacturer’s printer.
Choose the next investigation from the comparison
| Observed result | Useful next question | Keep separate |
|---|---|---|
| One-way clean; two-way edges doubled | Which approved directional target and preset apply? | User correction versus service-only mechanical adjustment |
| Both modes show the same missing features | Is the nozzle pattern acceptable? | Jet evidence versus direction offset |
| Error varies across the sheet | Is media height, support or motion changing by position? | Geometry versus a single correction value |
| Bands follow media advance | Does the approved feed test show an advance error? | Media-feed calibration versus opposite-direction placement |
These are investigation branches, not automatic diagnoses. A correction that improves one patch can hide a changing media condition elsewhere. Inspect the whole approved target, not only the sample that looks best.
Select a target value without guessing
Confirm whether alignment is operator-accessible, automatic or reserved for service. Read the target using the exact selection criterion in the machine instructions. Different targets ask for different comparisons; the darkest block is not necessarily the correct answer. If every candidate looks poor or an extreme value is needed, preserve the print and seek review instead of repeatedly extending the correction.
Roland’s BN-20D setup instructions treat bidirectional correction and media-feed correction as distinct tasks. We keep that distinction here without transferring its menu sequence or sample correction numbers to packaging equipment.
Do not lose the result when the next job starts
Record where the approved adjustment is stored: the machine, a media preset, print mode or software setting, as applicable. After saving, repeat the target and a representative job with fine text and edges. Confirm the result using the normal job-loading process so a different preset does not silently replace the approved condition.
If changing media height was part of the work, consult the head-height guide and the installed manual for the required rechecks. Physical head mounting, encoder work and carriage adjustments are not routine substitutes for selecting a printed target.
What we need for a useful alignment discussion
Send the exact machine configuration, current media preset, readable nozzle pattern, labeled one-way and two-way prints, original and changed settings, and whether the error varies by position. Include a real packaging job after calibration. Clean print placement still needs separate verification against cutting or forming registration.
For the equipment context, see our digital printing equipment. Use the inquiry page to share the comparison and confirm which alignment features are actually supplied with your proposed or installed system.