The most important implementation resource for barcode identification are the over 100 GS1 Member Organisations in countries all around the world. This guide takes new barcode users through the basic steps they must take to begin using barcodes.
Before a company can begin using barcodes, they must first assign the numbers that go inside the barcode, called GS1 Identification Keys. The first step in assigning a GS1 Identification Key is to obtain a GS1 Company Prefix from a GS1 Member Organisation. The GS1 Company Prefix provides a way for companies to create identification keys for trade items, logistic units, locations, parties, assets, coupons, etc. which are unique all around the world. GS1 Company Prefixes are used by 1,3 million companies worldwide as the basis for creating unique numbers to identify everything in the supply chain.
For information on the way to obtain a GS1 Company Prefix see 'Need a GS1 barcode'
After receiving a GS1 Company Prefix, a company is ready to begin assigning identification numbers to their trade items (products or services), themselves (as a legal entity), locations, logistic units, individual company assets, returnable assets (pallets, kegs, tubs), and/or service relationships.
The process is simple. Your local GS1 Member Organisation can provide you with specific information about how many numbers you can assign based on the length of your GS1 Company Prefix.
See the GS1 Identification Keys page for short introductions on the role and characteristics for each of the GS1 keys.
To begin, you should decide what you are barcoding and if the barcode will carry static or dynamic information inside it.
If the information is static (always the same), the barcode can be printed using traditional printing presses directly on the package (e.g., paper milk carton) or on a label that is applied to the package (e.g., label on a gallon milk jug.)
If the information is dynamic then either digital or a combination of digital and traditional printing will be required.
Your local GS1 Member Organisation is there to assist you in making the right selection, and many Member Organisations can also help you find a printing company in your local area.
The specifications for barcode type, size, placement, and quality all depend on where the barcode will be scanned. By knowing where your barcode will be scanned you can establish the right specifications for its production.
Barcodes to be scanned at the retail point-of-sale will need to support omni-directional scanning.
If the barcode will be scanned at point-of-sale as well as in the warehouse, you will need to use a symbol that accommodates point-of-sale scanning, but printed in a larger size to accommodate scanning in the distribution process.
Barcodes on healthcare items to be scanned in hospitals and pharmacies do not require omni-directional scanning, unless the items are also scanned at retail Point-of-Sale.
Selecting the right barcode is critical to the success of your barcode implementation plan, but here are some high level tips:
There are other factors to consider so contact your local GS1 Member Organisation to see what implementation products and services they offer.
See the GS1 barcodes page for an overview of the key characteristics for each of the GS1 barcodes.
After the correct barcode symbol is specified together with the information to encode in it, the design stage begins. The size of the symbol within the design will depend on the symbol specified, where the symbol will be used, and how the symbol will be printed.
The X-dimension is the specified width of the narrowest element of a barcode. X-dimensions are used together with the symbol heights to specify the permissible symbol sizes.
For each scanning environment the relevant symbols are listed with their target X-dimension and corresponding target height. Besides the target sizes also the allowed minimum and maximum sizes are specified.
EAN/UPC Symbols are designed for scanning by retail omni-directional scanners. This means that EAN/UPC Symbols have two segments which are taller than they are wide. There is a fixed relationship between symbol height and width. When one dimension is modified, the other dimension should be altered by a proportional amount.
The final major consideration for symbol size is the capability of the selected printing process. The minimum size (magnification) and correct Bar Width Reduction (BWR) for a symbol varies by printing process and even from press to press. Printing companies should establish a minimum symbol size (magnification) and BWR to achieve acceptable and repeatable quality results.
EAN/UPC symbols are suitable for omni-directional scanning since they can be read from all directions by a fixed scanner.
See GS1 General Specifications, “GS1 System Symbol Specification Tables” in section 5 for information on the allowed sizes of all GS1 Symbols based on the application where they are used. Symbol Specification Table 1 provides the details for the retail point-of-sale scanning environment.
The text beneath a barcode, called Human Readable Interpretation (HRI), is important because if the barcode is damaged or of poor quality to begin with, then the text is used as a back-up.
Here are some of the most frequently asked questions on HRI:
Does the Human Readable Interpretation need to be a certain size?
The human-readable text must be clearly legible and in a size proportional to the symbol size.
Is the Human Readable Interpretation supposed to be above or below the symbol?
HRI should be placed below the barcode and grouped together wherever physically possible while maintaining the HRI legibility and minimum barcode height.
I see parentheses around the Application Identifiers (AI) under some barcode symbols. Are they supposed to be there and are they encoded in the bars and spaces of the symbol?
All AIs must be enclosed in parentheses in the Human Readable Interpretation, but the parentheses are not encoded in the symbol.
How many digits do I print beneath the EAN/UPC Symbol in the Human Readable text?
See the GS1 Human Readable Interpretation (HRI) Implementation Guide for more information.
The optimum colour combination for a barcode symbol is black bars with a white background. If you want to use other colours, the following may help you in choosing satisfactory ones:
As explained, black bars and white spaces are the optimal combination, but other colour combinations can be used. Consult an experienced printing company recommended by your GS1 Member Organisation for additional guidance.
When discussing symbol location we are referring to the symbol placement on the design.
When assigning symbol placement first the packaging process should be considered. You should consult the packaging engineer to make sure the symbol will not be obscured or damaged (e.g., over a carton edge, beneath a carton fold, beneath a package flap, or covered by another packaging layer).
After determining the proper placement, the printing company should be consulted. This is because many printing processes require barcodes to be printed in a specific orientation to the feed direction of the web or sheet.
When using flexographic printing, the bars should run parallel to the press direction. If the bars are required to run perpendicular to the press direction check to ensure the symbol is not distorted.
When using either silk screen or rotogravure printing processes, the symbol should be aligned parallel to the cell structure on the screen or gravure plate cylinder to provide the smoothest bar edge possible.
To determine the proper location for GS1 barcodes refer to the placement rules in section 6 of the GS1 General Specifications.
ISO/IEC 15416 Barcode Print Quality Test Specifications for Linear Symbols describes a method for assessing the quality of barcode symbols after they are printed. An ISO-based verifier looks at the symbol in the way a scanner does, but goes further by grading the symbol's quality.
GS1 utilises the ISO/IEC method, but specifies the minimum grade necessary for every GS1 barcode based on which symbol is used, where it is used, or what identification number it is carrying. In addition to the minimum grade, GS1 also specifies the verifier aperture width and wavelength.
Setting up different minimum specifications is similar to a university using a standardized test to determine whether applicants qualify for admission. Several universities may utilize the same standardized test, but each sets the minimum score necessary for its applicants to be admitted.
GS1 General Specifications Section 5 provides a quick reference list of symbol quality specifications depending on the symbol type, the application, and the GS1 identification key the symbol is carrying.
GS1 Members may choose to perform their own quality control of barcode production. Today, many GS1 Member Organisations offer barcode quality verification services.