• Barcode Ireland Team

Better barcode label quality

A barcode is only functional if it can be read, without error, by a barcode scanner or camera.

Indispensable barcodes provide accurate item identification, accelerated data acquisition, prevent input errors and control entire systems - across industries.

Fortunately, end users have some options in improving crucial barcode label reading precision.

Select the correct barcode

There are many different barcode symbologies across the 1D and 2D categories and it’s important to select the correct one fit for purpose. 1D barcodes such as the EAN-13 and UPC-A used in retail, code small amounts of text whereas 2D barcodes can hold upwards of 4000 text characters or 7000 digits.

A list of symbologies and their use cases are described in our blog 'Which barcode is right for you?' https://www.barcodeireland.ie/post/which-barcode-is-right-for-you and worth considering at this point along with the space available on the product packaging. If there is very limited space then the EAN-8 which contains a minimal 8 digits may be used. Size is also a consideration when printing barcodes larger for readability.


Each symbology was developed with specific rules regulating the encoding and defining the size of the bars, the distance between the bars, the size of the visually (human) readable text, the aspect ratio and the total size of the symbol.

As label elements are freely moveable and resizable, a barcode symbol that is not easily readable or not readable at all can easily be created. If the symbol becomes too wide or is truncated, then the original design specifications will become compromised and readability no longer guaranteed.

High colour contrast

The most widely recognised colour formatting of barcodes is solid black bars on a white background. This format scans more reliably than any other colour combination. Scanners recognise and read the bars by using infrared light, distinguishing the contrast between the colours. Certain barcode colour combinations are particularly unfavourable such as red on white or black on blue. The best contrast is achieved with a black barcode on a white, non-transparent background.

Further information on the above is described in our our FAQ's 'Sizing, Dimensions and Colour guide' https://www.barcodeireland.ie/dimensions-and-sizing

The readability issue surrounding the need for high contrast extends to the packaging material. As the barcode can be printed directly on or embedded in the packaging material, the latter effectively serves as the background impacting barcode recognition.

The nature of the substrate is a great concern and not just relative to the colour. Texture and reflectivity can also have an impact. Glossy materials combined with adverse lighting conditions can cause reflections and consequently no-reads, as do backgrounds with busy and inconsistent patterns such as metallic surfaces.

The ‘Quiet Zone’

In order for a barcode to scan accurately there must be adequate clear areas around the barcode. This is the ‘quiet area’ which informs the scanner or camera where the barcode begins and ends. This area must be at least 5 times the width of the narrowest bar. Ensure that finishes such as lamination do not disturb the quiet zone.


The location of the barcode involves where it is physically located on the product or packaging. It should be placed on a clear, unobscured part of the product for convenient and accurate readability. Consistently positioning the barcode on a specific part of packaging will ensure easy detection.

Each scanning environment has its own particular barcode placement demands. Printing direction and surface types should be taken into consideration. For example, if barcodes are scanned at the retail POS, omnidirectional scanning should be employed. If the same barcode is to be scanned in the warehouse as well, then this should be printed in a larger size assisting the accommodation of scanning in the distribution process.

Its important to be aware that scanners have specific focal lengths allowing scanning within a certain reading distance range.

Print quality

Printing is a crucial element in creating readable barcode labels. If there are issues with scanning barcodes, it is mostly due to poor printing.

Linear barcode symbols such as the EAN-13 and UPC-A become unreadable if only one of the bars is damaged or printed incorrectly. If using a label printer, check the thermal printing process. Thermal transfer direct prints are more durable than Direct thermal prints as the label paper is sensitive to heat, abrasion and light.

The printer itself can reduce the print quality if the nozzles and heating elements are dirty or damaged. Try cleaning or replacing the printhead.

2D barcodes such as the data matrix barcode are less complicated than 1D linear barcodes. Due to high fault tolerance, it remains legible even when up to 30% of it’s code is damaged.

The label material will correlate with speed time should this be a priority. Synthetic material will not be printed in high quality above 6 IPS (inches per second) or 5.24cm. A special wax tape will be required to print at 12 IPS or 30.48 cm.

For faster printing, the darkness will necessarily increase to ensure barcode quality. The use of high quality ribbons consume more energy and use more ink to achieve darkness at higher speeds.

DPI (Dots Per Inch) is an important consideration when printing very small fonts or detailed graphics. For label quality, a very smooth shiny or synthetic material will be required.

Other defects

Physical defects in a barcode can include missing ink, extra ink, ink in the wrong areas and foreign matter such as pen marks, grease, glue and dirt. These can lead to the barcode scanner interpreting the presence or absence of a bar inaccurately. Physically checking your printed barcodes will ensure that high quality, defect free symbols will be implemented.

The printed resolution of barcodes should match the scanner’s software settings to avoid poor recognition.

Environmental requirements

Where your product will be stored will assist in determining the choice of label material and printing solution. If products are outside and exposed to the elements, synthetic material by thermal transfer would be preferable ensuring durability and flexibility. Direct thermal transfer for interior items.

Time and temperature

Adhesives play a significant role in the effectiveness of labels. Extremes of temperature impact their effectiveness.


Labels may become unreadable due to abrasion and choosing a label with a higher resin content will preserve strength.

Products exposed to weak to moderate chemicals such as bleach, alcohol, (or even water) will require a heat transfer method, whilst those exposed to more aggressive chemicals such as acetone and xyline require a resin tape solution for durability.

These environmental considerations along with the intended service life of the barcode label will determine the best solution. Direct thermal is the best option if products are stored for less then 6 months, in standard temperatures and a dry environment. Exposure to extreme temperatures, aggressive chemicals and humidity will require thermal transfer labels.

Our barcodes work internationally. Should you require barcodes for your products, please visit our Buy page www.barcodeireland.ie/buy, or contact us on info@barcodeireland.ie or through the contact form on our website www.barcodeireland.ie/contact and let Barcode Ireland help your business.







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