What is Barcode verification?

Barcode Verification measures the printed quality of the Barcode to international (ISO) standards. This is the Barcode standard used by retailers worldwide. According to international standards, Barcode Verification is mandatory for all companies either designing or printing their own Barcodes, ensuring that an acceptable image is created.

Despite the complex nature of Barcode Verification equipment it should be simple to use and display the results in clear, easy to interpret terms. The Barcode Verifier should be the Barcode expert in your organization, removing the burden of Barcode knowledge from your staff. If the format of the Barcode is incorrect, the size of the Barcode too large or too small or the Barcode print quality unacceptable, the Barcode symbol will fail to scan. The supply chain is broke. The number needs to be entered manually - perhaps incorrectly. A customer incorrectly charged. Wrong goods ordered or dispatched.

In many cases a poorly printed Barcode is worse than no Barcode at all!

Why verify?

Barcode quality is vital, as every time a Barcode fails to scan, the costs are incurred. At best the Barcode data is required to be input manually whilst at worst deliveries are rejected.

A recent survey by the e-centre (EAN UK) put the cost of poor quality Barcodes at over £500 million. Until recently, many retailers have accepted these unnecessary Barcode costs as a 'fact of trading life'. However, an ever increasing number of major retailers are now taking a very different approach to poor Barcode Verification, passing these costs back to suppliers. Goods are returned and fines are imposed. For repeat offenders the ultimate sanction can be, and has been, delisting the supplier!

Insurance:

At its most basic level, Barcode Verification is an insurance policy helping to assure you that your Barcode will scan first time at all levels of the supply chain, thus enhancing your supplier/customer relationship. But it's more than that. As part of an effective QA system it can help you win business. Are your competitors using Barcode Verification? Are they questioning the quality of your Barcodes with your customers? Is it affecting your Barcode business?

Why Can't I Just Use A Scanner?

Scanning is no substitute for Barcode Verification as no two Barcode readers are identical. They vary from wands to lasers to cameras, from manually operated to automatic. Ambient light will vary as will the distance of scanning. A Barcode that is checked with a wand gives no guarantee that it will be readable with another wand, let alone a later based unit.

A Barcode Verifier is a scientific device, taking precise measurements of each individual bar and space and the amount of light reflected from each. More advanced Barcode Verifiers will automatically identify the symbology and magnification, check data structure and validate the content as well as providing diagnostic information. It is all very well knowing that your Barcode is incorrect but a Barcode Verifier must be able to identify the problem to allow you to take the necessary corrective action.

Why was the ISO/CEN/ANSI method introduced?

Prior to the current ISO standard of Barcode Verifying printed Barcode symbols, only two factors were taken into consideration:

Dimensional accuracy of the bars and spaces.
Reflectance values of the bars and background (PCS.)
This traditional method would have been a reasonable way of assessing the print quality of the Barcode, except that there was no agreed way of determining where bar edges actually were or how and where reflectance measurements should be made. As well as this, Barcodes where bring measured with differing beams of light (apertures). Both of these factors resulted in a wide variation of results between Barcode verifiers.

With the variety of uses for Barcodes and the wide range of printing techniques used, it was felt that a more scientific approach was needed. In particular it was noted that different Barcode scanners and the differing environments in which these were used resulted in some aspects of poor Barcode print quality being more significant than others. Simple Barcode reflectance measurements were also found not to be helpful when the contrast might vary within the Barcode symbol. A definition of where a bar-space transition actually occurred was required as were specific aperture sizes dependent upon the symbology and size of Barcode.

These were then the main elements of the method that was initially written up as an ANSI Barcode standard. This was then adopted by CEN and eventually became an ISO Barcode standard. A Scan Reflectance Profile (an analogue graph of reflectance values of a defined wavelength of light from a Barcode symbol across a scan path) was to be analysed and specific measurements made from this profile in order to grade the scan. It was also specified that a single scan was not enough for an overall symbol grade.

This Barcode Verification method has proven to be thoroughly scientific approach but one that is also accepted and generally understood by users of Barcodes throughout the world. The Barcode grading method is also easy to understand and different grade requirements can be set for various applications of Barcode technology without the method needing to change. In recent testing of Barcode Verification equipment from various manufacturers, the method has also proved to solve the main problem with the traditional approach, as it was found that different pieces of Barcode Verification equipment gave the same results when applied to reference symbols.

What is checked and what is not checked?

Checked with Barcode Verification:

- Reflectance
- Contrast
- Decode
- Light margins
- Bar gain
- Defects
- Check digits

Not checked with Barcode Verifiers:

- Human readable
- Location
- Height
- Truncation
- Orientation

Advanced Barcode Verification Checks:

- Magnification (X Dimension)
- Wide to narrow bar ratio
- Application standards (coupons, variable weight etc)
- UCC.EAN-128 data validity
- RSS data validity
- Full encodation
- Integral check digit
- Data format

Case study: What are the common problems with on-demand printers?


As the number of people printing outer case Barcodes on-demand has increased, so has the number of product rejections. The vast majority of these are a small number of basic Barcode print quality issues on thermal printers that should be identified prior to dispatch and should never have entered the supply chain.

Void un Barcodes
Labels printed in 'ladder format': White lines running parallel to the length of the Barcode. Some retailers are now operating a zero tolerance approach to such Barcodes. See below.


Labels printed in 'picket fence format': White lines running through the height of the Barcode. Massive problem that can mean that part of the bar (or even a whole bar) is missing. Leading to failure for the ISO grades defects, decodeability and decode. See below.


Bar gain. Incorrect speed and/or temperature settings. Result: Bars too wide, spaces too small. Generally causing the Barcode to fail for decodeability.
Light margin infringements: Barcode too big for the label; incorrect positioning on label; text too close to near Barcode. Result: An automatic grade F for decode.

Managing Quality:

Barcode quality is perhaps more important now than ever before. The use of automated systems in warehouses and distribution centres is becoming more widespread. For these systems to work effectively, the format, data content and the print quality must all be accurate. The more sophisticated forms of Barcodes such as UCC/EAN-128 demand an extra level of quality management.

The only way to guarantee both the print and quality and the data of your Barcode is by using the correct equipment. An ISO grade Barcode Verifier will check that the printing of your Barcodes is of an acceptable quality. Some will also be able to give you details of the UCC/EAN-128 data content as well as matching the Barcode number to a product; ensuring that your packaging will not be a problem to your trading partners. This cannot be done by eye or with a standard Barcode scanner.

By incorporating Barcode verification into your quality assurance systems you can ensure that your Barcodes read first time, every time.

Be part of the solution, not the problem!