Ten Steps to Bar Code Implementation
Step 1: Get a GS1 Company Prefix
Before a company can begin using bar codes, they must create the numbers that go
inside the bar code. These numbers are called
GS1 Identification Keys. The first step
in building a GS1 Key is to obtain a GS1 Company Prefix from a
GS1 Member Organisation.
GS1 Company Prefixes are used to
identify over 1 million companies today and form the foundation of uniquely identifying
everything in the supply chain. To obtain a GS1 Company Prefix contact the
GS1 Member Organisation in your country.
Step 2: Assign Numbers
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 (returnable
pallets, kegs, tubs), and service relationships.
The process is fairly simple. You learn about
how to format each number then use the
GS1 Company Prefix in combination with reference numbers you assign. 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.
Step 3: Select a Bar Code Printing Company
To begin, you should decide what you are bar coding and if the bar code will carry
static or dynamic information inside it. An example of static information would
be simply a product identification number (GTIN) on a cereal box. An example of dynamnic
information would be printing serial numbers on product labels.
If your bar code has static information and you need a large volume of labels then
you will likely ask a printing company to print your labels. If you need a small
volume of labels or need to print labels with dynamic information you will likely
need an on-demand printer like a laser printer in your office or thermal transfer
printer in your warehouse.
Knowing how you will print your bar code is an important question to answer in developing
a good bar code implementation plan. Again, 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 printer in your local area.
Step 4: Select a "Primary" Scanning Environment
The specifications for bar code type, size, placement, and quality all depend on
where the bar code will be scanned.
There are four basic scanner environment scenarios for trade items:
- Product package scanned at the retail point-of-sale (POS)
- Product package scanned in a general distribution
- Product package scanned at POS but also scanned in distribution
- special environments like medical device marking
By knowing where your bar code will be scanned you can establish the right specifications
for its production. For example, if a product package is scanned at Point-of-Sale
(POS) and in general distribution, you will need to use an EAN/UPC symbol to accomodate
POS but print it in a larger size to accomodate distribution scanning and ensure
the placement meets automated distribution scanning requirements.
You can find more information in the GS1 General Specifications (available from
your local GS1 Member
Organisation, for on scanner environments see Section 5.4, for symbol
placement consult Section 6.0).
Step 5: Select a Bar Code
Selecting the right bar code is critical to the success of your bar code implementation
plan, but here are some high level tips:
- If you bar code a trade item that will be scanned at the retail point-of-sale (POS),
you must use an EAN/UPC symbol.
- If you are printing a bar code with variable information like serial numbers, expiry
dates, or measures, then you will use GS1-128, GS1 DataBar (RSS), or in special
cases Composite Component or GS1 DataMatrix symbols.
- If you just want to print a bar code carrying GTIN on a corruaged carton, ITF-14
may be the choice for you.
There are other factors to consider so contact your local
GS1 Member Organisation to see what
implementation products and services they offer.
Step 6: Pick a Bar Code Size
After the correct bar code 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.
EAN/UPC Symbols
EAN/UPC Symbols differ from ITF-14 and UCC/EAN-128 Symbols because they are scanned
by retail omni-directional scanners. This means that EAN/UPC Symbols have a fixed
relationship between symbol height and width. When one dimension is modified, the
other dimension should be altered by a proportional amount.
Because of this relationship, EAN/UPC Symbols have a nominal height and width specified.
A range of allowable sizes from 80% to 200% of the nominal size are also specified
and a figure showing the range of dimensions can be found in
GS1 General Specifications, Section
5.1, Appendix 7. This range of sizes is often referred to as ""magnification factors""
on purchase orders specifying EAN/UPC Symbol sizes. The minimum, nominal, and maximum
magnification for EAN/UPC Symbols are shown in Figure 1.3.1-1.
EAN/UPC Magnification
Minimum (80%)

Nominal (100%)

Maximum (200%)

In order to decrease the amount of space EAN/UPC Symbols take up on a design, a
decreased symbol height might be specified. This process, called truncation, is
not permitted within EAN/UPC Symbology specifications and should be avoided. This
is because of the negative impact it has on scan rates for retail omni-directional
scanners. For more information on truncation, refer to the
GS1 General Specifications, Section
6.3.3.4 (available from your local
GS1 Member Organisation).
When EAN/UPC Symbols are used in logistics (shipping and distribution) as well as
at the Point-of-Sale (POS), the range of magnification allowed is limited to between
150% and 200%. An example of this would be the symbol on a carton used for a large
appliance (e.g. TV or microwave oven).
ITF-14 and GS1-128 Symbols
ITF-14 and GS1-128 Symbols also have a range of sizes specified. ITF-14 and GS1-128
Symbol sizes are often specified by the width of the X-Dimension instead of magnification
values. You can find information on the sizes for ITF-14 and GS1-128 Symbols based
on the application where they are used or the identification number they carry in
GS1 General
Specifications, Section 5.4.2 (available from your local
GS1 Member Organisation).
Consideration of the Printing Process
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.
As always, be sure to contact your local
GS1 Member Organisation for additional implementation
guidance.
Step 7: Format the Bar Code Text
The text beneath a bar code is important because if the bar code is damaged or of
poor quality to begin with, then the text is used as a back-up.
Click here for some examples of text formatting.
The best way to cover questions about the Human Readable Interpretation for GS1
System Bar Code Symbols is to answer some of the more frequently asked ones.
Does the Human Readable Interpretation need to be a certain size?
The OCR-B font was originally specified for use with EAN/UPC Symbols, but GS1 System
specifications now permit any font as long as it is clearly legible. For detailed
size specifications for EAN/UPC Symbols, see
GS1 General Specifications Section 5.1,
Appendix 6 (available from your local
GS1 Member Organisation).
The human-readable text for ITF-14 and GS1-128 Symbols must be clearly legible and
in a size proportional to the symbol size as per
GS1 General Specifications Section 5.2.1.6
(ITF-14) and Section 5.3.7.4 (GS1-128) (available from your local
GS1 Member Organisation).
Is the Human Readable Interpretation supposed to be above or below the symbol?
It depends on the symbol you are using. For EAN/UPC Symbols, refer to the drawings
in the GS1 General
Specifications Section 5.1, Appendix 6. For ITF-14 and GS1-128 Symbols
the text can be printed above or below the symbol as per
GS1 General Specifications Section 5.2.1.6
(ITF-14) and Section 5.3.7.4 (GS1-128) (available from your local
GS1 Member Organisation).
Can I put spaces in between the text characters?
Yes, in fact, EAN/UPC Symbols specify spacing per the drawings referenced in the
question above. Many companies specify spacing in between ITF-14 and UCC/EAN-128
Human Readable Interpretation. This makes the text easier to read, remember, and
key enter. While including spaces is perfectly appropriate for the Human Readable
Interpretation, the spaces must not be encoded into ITF-14 or GS1-128 Symbols.
I see parentheses around the Application Identifiers (AI) in the GS1-128 Symbol.
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 per the
GS1 General Specifications Section 5.3.7.4.
(available from your local
GS1 Member Organisation).
How many digits do I print beneath the EAN/UPC Symbol in the Human Readable
text?
You must, absolutely and without exception, print 12 digits, no more, no less, below
the UPC-A Symbol.
You must, absolutely and without exception, print 13 digits, no more, no less, below
the EAN-13 Symbol.
You must, absolutely and without exception, print eight digits, no more, no less,
below UPC-E and EAN-8 Symbols.
Step 8: Pick a Bar Code Color
The optimum color combination for a bar code symbol is black bars with a white background
(spaces and Quiet Zones). If you want to use other colors, the following may help
you in choosing satisfactory ones:
- GS1 Bar Code Symbols require dark colors for bars (e.g., black, dark blue, dark
brown, or dark green).
- The bars should always consist of a single line color and should never be printed
by multiple imaging tools (e.g., plate, screen, cylinder).
- GS1 Bar Code Symbols require light backgrounds for the Quiet Zones and spaces (e.g.,
white).
- In addition to light backgrounds, ""reddish"" colors may also be used. If you have
ever been in a darkroom with red lighting and tried to read red copy, you know it
can virtually disappear. This is also true of similar colors such as orange, pink,
peach, and light yellows. Given the fact that most bar code scanners use a red light
source, you can quickly see why these colors may be suitable for backgrounds, but
should be avoided for bars.
- In many cases the symbol background is not printed. It is the color of the substrate
that is being printed. If the symbol background is printed beneath the bars, the
background should be printed as solid line colors.
- If you use multiple layers of ink to increase the background opacity, each layer
should be printed as a solid.
- If you use a fine screen to deliver more ink to the substrate, be sure there are
no voids in the print caused by the screen not adequately filling in.
Again, by staying with black bars and white spaces, you have selected the optimal
combination, but other color combinations can be used. Consult an experienced printer
recommended by your GS1
Member Organisation for additional guidance.
Step 9: Pick the Bar Code Placement
When discussing symbol location we are referring to the symbol placement on the
design. When assigning symbol placement 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). To determine the proper location for GS1
bar codes, see the following sections of the GS1 General Specifications (available from
your local GS1 Member
Organisation):
- Logistics Label Design, Section 2.2.4.4
- General Placement Principles, Section 6.2
- General Placement Guidelines for the Retail Point of Sale, Section 6.3
- Placement Guidelines for Specific Package Types, Section 6.4
- Symbol Placement for Clothing and Fashion Accessories, Section 6.5
- General Format Guidelines for Clothing and Fashion Accessories Labels, Section 6.6
- General Placement Guidelines for Symbol Placement on Items used in Distribution,
Section 6.7
After determining the proper placement, the printing company should be consulted
before assigning the symbol rotation. This is because many printing processes require
bar codes to be printed in a specific orientation to the feed direction of the web
or sheet.
If possible, when using flexographic printing, the bars should run parallel to the
press web direction or in the picket fence orientation. If the bars are required
to run perpendicular to the press direction or in the ladder orientation, try to
avoid distorting the symbol for the plate roll circumference.
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.
For more information or to obtain a copy of the
GS1 General Specifications, contact
your local GS1 Member Organisation.
Step 10: Build a Bar Code Quality Plan
ISO/IEC 15416 Bar Code Print Quality Test Specifications for Linear Symbols
describes a method for assessing the quality of bar code 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 bar code 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.
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