Barcoding Knowledge Centre

Issue

Barcodes that have been printed using incorrect colour combinations, often red bars on a pale background, or reversed images where the bars are white against a coloured background, will not scan.

Traditional barcode readers use red light, and of course are looking for contrast. Black or Blue on red will stand out to the reader, however red or yellow for example will not stand out.

Advice

You can test if the barcode will be readable by looking at the code through a red lens.

Use ISO/IEC 15426-1 Compliant Verifiers.

Issue

Printhead failure will leave white lines through the print in the direction of feed.

Printheads will fail faster when printing in ladder format as per this image.

Element failure when printing in picket fence can change the code characteristics.

Advice

When white lines like this appear the printhead must be replaced.

Always print codes in picket fence. Codes will be sharper and printheads last longer.

Bearer bars should be added to top and bottom of the code. When white lines appear in these, replace printhead.

Issue

Barcodes can be missed by fixed readers in automated systems if they are too small.

Some readers won’t read at all if the code is too condensed.

Advice

Ensure the bars are at least 32mm in height plus the bearer bars.

Use a minimum barcode magnification of 50% for labels printed using thermal transfer.

Issue

Peeling is usually caused by extreme heat which dries out the adhesive, degrading labels due to age, or wrong adhesive for the application.

Advice

Get a clear understanding of the label life cycle and what conditions it will be exposed to.

Our media specialists will specify the correct solution based on the above.

Issue

Creased labels cause great difficulties when trying to read them. Creasing is generally caused by human error when hand labelling. Creasing can also be caused by uneven and contaminated surfaces, so you sho

Creased labels are common in automatic corner wrap applications.

Advice

Look for best consistent area on your packaging to apply labels.

Automated print and apply will give uniform application, improved efficiency and cost savings.

2 Labels on 2 adjacent faces. Better application, better print and more options.

Issue

Printing a barcode in ladder format – the wrong orientation will result in fussy trailing edges on the bars. This makes reading more difficult and will reduce overall grades when checked with a verifier.

Printing barcodes in the wrong orientation can cause excessive wear of printheads.

Advice

Barcodes should be printed in a 'picket fence' orientation, not a 'ladder' as shown in the picture to the left.

This assumes the label in the image is printed narrow edge leading.

Issue

Barcode readers must see the whole code to read and decode accurately. Otherwise, the code image will fail to read.

Advice

Quiet zones or clear space should be present at each side of the code.

Apply the logic of 10 times the minimum bar width as a minimum for quiet zones.

Avoid applying the code to your product within 19mm of a vertical edge.

If design is OK, but the print is falling off-label, check the printer and media tracking.

Issue

In some cases, this simply can’t be avoided.

Advice

Configure the readers to read the specific code type you are looking for (GS1-128 for example) and ignore other types.

Issue

A Global Location Number (GLN) is a unique number that is assigned to locations to enable them to be identified uniquely worldwide. These GLNs can be used to identify any legal, physical and functional locations. GLNs are reference keys to computer files where information about the company or location can be found. The GLNs replace the names and addresses of locations and are particularly useful when automating processes; they allow computers to route information to the correct destination with no manual involvement. GLNs must be used when identifying locations and trading partners within Electronic Data Interchange (EDI) business messages and data pools, and they can also be used in barcodes to identify a physical location or to provide relevant information for delivery or invoicing purposes.

Advice

GLNs can be used to identify any locations that you need to be uniquely identified for administrative and trading purposes. These can be both internal locations, and locations that your trading partners will use. GLNs provide a single method for location identification for all companies in the supply chain, thereby removing the unnecessary costs and errors inevitable when many different schemes co-exist. GLNs can:

• Enable the unique and unambiguous identification of all worldwide locations
• Be allocated to any location in the supply chain
• Be shown in GS1-128 barcodes
• Be used within electronic business messages, and to identify all the parties using data pools
• Facilitate accurate and automatic processing
• Simplify data processing and reduce transmission costs and data storage costs for messages

Issue

Accurate product data is an essential component of a visible, secure, and sustainable supply chain – yet research has shown that 80 per cent of professionals have little idea how to measure the products they sell.

Advice

Without a recognised, uniform methodology for measuring products, it is obvious that there will be discrepancies from company to company. After all, how would trading partners know that they had both identified the same depth for an item? How would a retailer and a brand know if they are even using the same system to measure a product? It is for this reason that GS1 created their package measurement rules as a guide for all trading partners wishing to exchange data about product package measurements. They provide a common procedure for all and are intended to ensure global compatibility.

Issue

All Global Trade Item Numbers (GTINs) and Global Location Numbers (GLNs) end with a computer-generated check digit. This digit is the result of an algorithm (called the Modulo-10 algorithm) which uses the other numbers in the GTIN or GLN to ensure its correct composition.

Advice

When you look at My Numberbank you may think that the numbers are not in sequence. This is because the last digit is a check digit based on this calculation. The preceding digits are all in sequence. There is a useful online check digit calculator available at www.gs1uk.org and the calculator is in the Tools & Resources menu, but if you want to understand how the check digit is calculated then download the GS1 How To Guide to discover more.

Issue

A product whose price is dependent on a measurement which can constantly change can’t be identified by a standard fixed measure Global Trade Item Number (GTIN). Instead we have a standard national structure across retail, which has its own reserved prefixes. These prefixes mean that systems can be programmed to pick out the information necessary to calculate the price at a consumer level, or measurement information at a traded level.

Advice

A variable measure retail trade item is defined as an item whose price is continuously dependent on a measurement, e.g. its weight. Products that are divided into measurement bands and priced in steps according to the band into which they fall are NOT included. In this case each band should be allocated a standard fixed measure GTIN. Products that are commonly sold by weight or measurement include fish, fruit, cheese, vegetables, deli goods, carpets, timber and fabrics. There are two ways of identifying variable measure items; Download the GS1 How To Guide to discover more.

Issue

Using logistics labels to track pallets and other logistic units is an effective and essential part of supply chain management. Within the label, the SSCC is a unique serial number that is used to identify each individual pallet. GS1 logistics labels enable you to present information in a standard format that is recognised internationally. It uses GS1-128 barcodes to represent the SSCC for a pallet as well as certain types of information about the contents of a logistics unit. These labels can also be used on any units that are transported between companies. For example, drums of chemicals, rolls of fabric or paper, pallets of raw materials, part pallets, or individual traded units.

Advice

The SSCC provides a single way of uniquely identifying logistics units to make it simpler to track and trace products through the supply chain. You can also use GS1 standards to provide information about the contents of each logistics unit, which can be used in any trade and industry sector. The benefits of using SSCCs and the GS1 logistics label include:

• One label that’s used throughout the supply chain
• Improved control procedures in warehousing and distribution
• Unique identification for standard and non-standard pallets
• A consistent link with electronic data interchange (EDI) business messages
• Minimised labelling costs through the use of an international standard
• Automation and efficient handling of transport units and their contents
• Increased speed of processing deliveries
• Improved matching of deliveries against invoices

Issue

This quick guide helps you to improve the quality of barcode images on your packaging and products (consumer level). It can also be applied to outer packaging (traded level). It takes you through the best approach to solving your barcode image issues when they occur during the validation of your artwork or verification of your final product.

Advice

Getting the dimensions of your barcodes correct, the data encoded and suitable colour use in design are all important first steps. When creating your barcode at the design stage, we recommend you check out the Barcoding – getting it right guide at www.gs1uk.org/support to discover more.

Issue

Moving from barcoding your products to barcoding your cases or outer packaging can be confusing. You may have been requested by a new trading partner to start barcoding your cases in order for them to track and trace them throughout their supply chain. Cases are also referred to as ‘traded units’, ‘outer cases’ or ‘trade item groupings’ but these are all the same thing.

Advice

You have a few options when choosing the barcodes for your cases, all of these use the Global Trade Item Numbers (GTINs) we licence to you. It is important to make sure you choose the right one, depending on where they will be used and the product that they contain. Products may carry barcodes consisting of 8, 12 or 13 digits, which can be scanned at the point of sale. If cases of your product, for example, 6 bottles of fizzy drink, are to be sold in-store and scanned at the point of sale, then they will require a separate barcode to the individual product to enable the retailers system to tell the two apart. These are shown on the product using EAN or UPC formats. Cases not scanned at the point of sale may feature barcodes that are longer using GTIN-14s and, in some instances, include information such as expiry dates encoded within them. These are shown in ITF or GS1 128 formats.