Barcodes have become indispensable in manufacturing, logistics and trade. They accelerate data collection, prevent input errors and even control entire systems. But this form of industrial automation only works if barcode scanners and cameras can read your barcodes without errors.
Weber Marking Systems provides its customers with all the right tools for product marking and coding: from label printers and barcode labels to labeling systems and inkjet printers. We therefore know the pitfalls of barcode readability and would like to share some tips for you to prevent common causes of bar code failure!
1. Don’t violate quiet zones
For the scanner to accurately recognize the beginning and end of the code, there must be a sufficiently large white area around each barcode – the so-called ‘quiet zone’. This area should be at least 5 times the width of the narrowest bar. Make sure that even subsequent finishing (e.g. film lamination) does not disturb the quiet zone.
2. Print high-contrast
High-contrast prints are easier to capture by scanners. Avoid light-colored barcodes on light-colored backgrounds and dark barcodes on dark backgrounds. Certain barcode color combinations are also particularly unfavorable (e.g. red on white or black on blue). The best contrast is achieved with a black barcode on a white, non-transparent background.
3. Choose matte surfaces
Glossy materials such as lacquered cardboard, aluminum cans or film paper can affect readability, as they often do not optimally reflect the scanner’s infrared light or diffuse it too much. Try the following trick: Print the barcode inverted by reversing the colors. Instead of printing the black lines, print the white gaps!
4. Ensure proper print quality
If parts of the barcode are damaged, it is no longer readable by barcode scanners and cameras. If you are using a label printer, check your thermal printing process: Direct thermal prints are not very durable as the label paper is sensitive to heat, abrasion and light. Thermal transfer direct prints are much more durable.
Furthermore, the printer itself can reduce the print quality if, for example, the nozzles and heating elements are dirty or damaged. Try cleaning or replacing the printhead. Also, read our tips on how to check barcodes without a scanner to identify tricky printer errors with the naked eye.
You could also try a two-dimensional barcode type that is a little less complicated than the linear one: a data matrix code. Due to its high fault tolerance it remains legible, even if up to 30% of its code is damaged.
5. Follow specified standards
In some cases you will need to make sure that your barcodes will be accepted by other companies throughout the supply chain. Maybe even all over the world. This means that your barcode images must meet certain rules that specify your barcode’s print quality, bar height, colour and background as well as its position on the label or packaging. Organizations such as GS1, which drive the global development and standardization of barcodes, provide according guidelines, tools and services.
6. Make it easily accessible
First of all, your barcode must not be (partially) covered or obscured by any other objects during the scanning process. Also, you need to know that barcode readers have certain focal lengths that allow scanning only within their reading distance range. Even the angle, in which the reader is held or mounted in, can affect the readability. Therefore, make sure the barcode is easily accessible but also protected from dirt, buckling and any other damage risks.
Bonus tip: In order to identify many goods at the same time and without visual contact for scanning, RFID technology may be an alternative. The integrated RFID transponders in RFID labels are not only durable and robust, but also rewriteable.