Barcode Frequently Asked Questions
Are there different bar codes?
In a book published by Mr. Benjamin Nelson in 1997 there are
over 260 different barcodes symbol formats described. Many of
these symbols are rarely used currently because they have been
superseded by better symbols. There are three basic types of
barcodes, linear, 2D, and composite. Linear barcode symbols
are easily identified by their tall printed bars of varying
widths. There are many linear symbols but the ones used most
frequently are called UPC-A, UPC-E, EAN-8, EAN-13, Code 39,
Code 128, and ITF (Interleaved 2-of-5). Two dimensional barcode
symbols are broken into two major groups called Matrix symbologies
and Multi-row bar codes. Matrix symbologies look like a matrix
of printed dots and Multi-row bar codes look like linear barcodes
with very short bars stacked on top of each other. Composite
symbols are a category of barcodes that combine an interdependent
linear and 2D symbol.
What barcode do I use?
If you are developing a closed system strictly to be used within
your company, then the choice is yours. You need to analyze
what your requirements are as far as type of data (numeric,
alphanumeric) as well has how much space you have available
to print the code. If space is not constrained then the most
likely code is Code 128. Many industries are standardizing on
Code 128. If you have a space problem then you may want to evaluate
one of the matrix symbologies.
In general, it will cost you more for scanning equipment capable
of scanning a matrix symbol.
How do I print a barcode?
There are two major types of printing equipment used to print
barcodes, traditional pressroom equipment and electronic printing
equipment. For those who are printing the same barcode over
and over within their packaging graphics, the traditional pressroom
approach is widely used. For those who print many different
barcodes everyday or who print barcodes with information that
varies (e.g. shipping labels, apparel tags, or foodservice labels)
electronic printers are used. In order to print your own labels
and tags you need a printing system comprised of a printer capable
of printing barcodes, software to design your barcodes, and
labels, tags, and ribbons/toner.
Keep in mind that whatever technology you use, it is your responsibility
as the printer of these barcodes to verify that they conform
with industry specifications and will be readable with any scanner
that can decode the symbology you have printed. You can only
do this with a barcode verifier.
What size do I make a barcode?
For a closed system (where you control the scanning environment),
this is entirely up to you. You will simply use whatever size
you need it to be for your scanning equipment.
If you are trying to comply with an industry specification,
an application specification will define the size that is needed
in order to be in compliance. Most application specifications
are based on a particular scanning environment and call for
a specific barcode symbology, size of the narrow element, and
height of the code.
How do I know the barcode that I printed is good?
Many people take their barcode to a scanner to see if will scan,
but the only way to know for certain is by scanning the barcode
with a ANSI-based verifier. The difference between using an
ANSI-based verifier and a scanner to determine what is good
is the scanner only assures you that what you have printed can
be scanned by that particular scanner. With a verifier you will
know if the symbol you have printed is scannable by any scanner
in the world capable of decoding the particular symbology you
have printed.
In 1990, ANSI X3.182-1990 Barcode Print Quality Guideline was
published. ANSI X3.182 describes a method for assessing the
quality of barcode symbol using a verifier. Using the ANSI X3.182
method, various industry representatives specify the minimum
quality level necessary for barcode symbols depending on which
symbol is used, where it is used, or what identification number
it is carrying. In addition to the minimum quality level, they
also specify the verifier aperture width and wavelength to be
used.
Setting up different minimum quality levels 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 University sets the minimum
score necessary for their applicants to be admitted.
What color can I use for barcodes?
This will very much depend on the application. For in-house
use you can decide for yourself based on the scanability you
are able to achieve with different colors. If you are providing
something based on a customer's specification then they will
generally tell you what colors they want it to be. It is generally
best to avoid colors having red pigmentation if your customer's
scanners operate in a wavelength range from 630 to 680 nanometers
(visible red spectrum). For these scanners, bars printed in
black, dark blue, or dark green and spaces printed in white,
red, orange, purple, and yellow generally work well.
Depending on the scanner being used, the color may be of little
relevance. When the scanner being used has a light source above
900 nanometers (mostly industrial applications), it is more
important to make sure that there is carbon content in the ink
that is used.
If you are printing on a reflective substrate such as an aluminum
can, it may be possible to print the spaces and quiet zones
in white, red, orange, or light yellow and let the aluminum
show though as the bars. If you do, remember to print the human-readable
text in a dark color in case the scanner operator has a scanning
problem and has to key enter the information.
Reprinted with permission from AIM, Inc
www.aimglobal.org
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