Checking barcodes without a scanner

How to check barcodes without a scanner

When printing barcode labels, there are important things to consider to ensure faultless scans and efficient workflows throughout the entire supply chain. Make sure to read our 6 tips for better barcode quality for a start. What also influences the readability besides the design is the thermal printing process. In this post we will show you how to detect small errors quickly and with the naked eye!

First things first: Don’t forget about the printhead

High and consistent print quality is essential for barcode scanners to work best. Professional label printers deliver brilliant performances and are perfect for use within production and logistics. Just like any other labeling machines, they need some maintenance to keep them running smoothly. Make sure to clean the printhead regularly (accordingly to manufacturer’s instructions) to prevent the accumulation of dirt and residue.

Despite all care, however, the printhead wears out over time. It typically shows when the small heating elements start to fail, leaving blank burn lines cutting through the print image. These voids are fatal for barcode integrity: Even the smallest white line can result in major trouble with trade partners, cause chargebacks or slow down your intralogistics operations.

Defective dot in label printer
A defective heating element on a printhead

Barcode verification systems provide a reliable way to evaluate the code’s quality and compliance, but are not necessarily used for smaller applications. The good news is that with the help of our tips and tricks you can detect common errors without a scanner! But first, let us tell you why the barcode orientation plays a crucial role in this scenario.

Barcode orientation matters: fence vs. ladder style

Depending on the label printer and label layout, the barcode will have a specific position and orientation on the label. If the stripes of the barcode point in printing direction, it is called a ‘picket fence’ barcode. If, on the other hand, the stripes are transverse to the printing direction, it is a ‘ladder’ barcode. The following illustration clearly shows why they are called this way:

To check fence barcode: add a verification line

Could you tell for sure if this following barcode is perfectly fine? Spoiler alert: it’s not.

Fence barcode

Here’s a little but effective trick: Insert a thicker, continuous line above the barcode:

Fence barcode with verification line

While an error in the upright bar is hardly noticeable, the error in the horizontal bar is immediately visible. It’s a tell-tale sign that a diode is defective or dirty.

To check ladder barcode: look out for white lines

If the barcode is rotated 90°, the fault will catch your eye instantly. The missing dot causes a white line across the entire barcode:

Ladder barcode with white line

But beware: Before you rotate the barcode, you should first check if it is suitable for the material combination used and the necessary printing speed. Here’s why: The heating elements of the label printhead are switched on and off very quickly at high printing speeds. However, each heating element has a certain inertia and remains a little warm even after being switched off. The barcode lines may therefore appear somewhat frayed which can affect the overall quality.

Find the perfect barcode printer

You don’t want to compromise on barcode printing? Weber Marking Systems is your official trade and service partner for renowned manufacturers of label printers such as Zebra, Sato, Epson, Novexx and Datamax. We will advise you personally to find the best solution for your needs!

Contact us now for a free expert consultation


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