Print-and-verify: every label checked before the pallet leaves
Barcode grading or full inspection
The question is not whether to inspect, but how far.
Every code is graded to ISO/IEC 15416 (linear barcodes) or ISO/IEC 15415 (2D codes such as DataMatrix and QR). The grade shows whether it will also read reliably at the customer’s site, not just in your own facility.
The inspection sees the whole label: text, codes, symbols and layout, compared with the approved template.
Both run directly on the line. If something deviates, the line stops before the pallet leaves. And because every inspection is measured, you can see over weeks how print quality develops.
Sample or inline: the difference is timing
Labels rarely get bad suddenly. They get worse slowly: a printhead wears, a material batch varies, a setting was changed for another job.
A sample check inspects what happens to be in your hand. If an error is missed, it often only shows up at the customer’s goods receipt.
Inline inspection checks what is being printed. An error shows up the moment the label leaves the platen.
If the result deviates, the line stops, the faulty label is rejected and reprinted before the pallet leaves.
Inline inspection produces a measurement result for every label. The only question is whether it is discarded or stored with the order.
Reading is not verifying
A scanner answers one question: readable or not. A verifier answers another: how well is the code printed? A barcode that reads today with a good scanner can fail with a weaker scanner at the customer’s site. The grade shows this gap before it becomes a problem.
The difference between light and dark areas.
How evenly this contrast is spread across the whole code.
Voids and spots in bars and spaces.
How closely bar and space widths match the specification.
Whether the reader reliably detects every edge and the bars are dark enough.
The weakest grade counts. For each scan line, the weakest parameter determines the grade. The overall grade is the average over several scan lines (ISO/IEC 15416).
From measurement to proof
The sentence “we check our labels” does not convince an audit. What convinces is one record per label:
The effort is smaller than it sounds, because the data is generated anyway. And it yields more than proof: a trend. Anyone who sees the grade over weeks can tell which printer is deteriorating and which material varies, and replaces the printhead before the pallet comes back.
Inspection results belong to the same order as the template. With OPAL Labelmanagement™, labels come from one source across the company, directly from the ERP if required. Our digital solutions show how inspection data feeds into validation and compliance.
What hardware, software, service and consumables contribute
Depending on the line, inspection sits in the printer or as a camera after printing. What matters is a printing system that suits the real environment and load, from the industrial printer in shift operation to the print engine in the applicator.
Many errors do not arise in the printer, but before it: wrong template, transferred values, different settings per site. With OPAL Labelmanagement™, labels come from one source across the company.
When the grade drops, that is a maintenance signal. Regular maintenance at intervals that suit your operation keeps print quality and availability stable, instead of reacting only after a complaint.
Fluctuating print quality often has to do with the combination of printer, setting, label and ribbon. We produce labels in-house and test adhesion, resistance and printability in our own laboratory.
When a sample check is enough
Not every line needs inline inspection. For small volumes, purely internal labels and no quality requirement from your customers, a regular sample check with a handheld verifier is often enough. Inline inspection makes sense where customers specify a grade, returns are expensive or proof per label is required.
Frequently asked questions
Can a scanner replace a verifier?
No. A scanner tells you whether a code was read. A verifier tells you how well it is printed, using a standardised method.
Which grade is sufficient?
That is usually set by your customer or your industry. If a minimum grade is specified, it is in your customer’s label specification.
Does this also apply to 2D codes?
Yes. For 2D codes such as DataMatrix and QR, ISO/IEC 15415 applies, with its own parameters.
What does full inspection check in addition?
Not just the code, but the whole label: text, codes, symbols and layout, compared with the approved template.
Standards: ISO/IEC 15416 (print quality of linear barcodes), ISO/IEC 15415 (print quality of two-dimensional codes).