Barcode FAQ & Tutorial
The industrial use of barcodes can be traced back as far
as the 1960s, in some cases as a means to identify railroad
cars. Common linear barcodes started appearing on grocery shelves
in the early 1970s as the UPC barcode to automate the process
of identifying grocery items. Today,
barcodes are just about everywhere and are used for identification
in almost all fields of business. When barcode technology is
utilized in business processes, procedures are automated to
increase productivity and reduce human error. Barcoding should
be used whenever there is a need to accurately identify or track
Radio Frequency Identification (RFID) is still in its infancy
as a technology, and implementation is usually many times more
expensive compared to that of barcoding. There are many additional
issues to consider with RFID such as those listed in the
Disadvantages of RFID section in IDAutomation's RFID FAQ.
However, RFID also has many advantages over barcoding. In some
cases, these advantages outweigh the disadvantages and high
cost of implementing RFID technology. Decision makers must carefully
consider whether RFID really provides an advantage the traditional
use of barcodes in their business model.
The type of barcode that should be used may depend on several
variables, including the following:
- Standards and mandates
- Purpose and use
- Data encoded
- Printing and/or decoding methods
There are several different types of barcode standards for
different purposes - these are called symbologies. Each type
of symbology (or barcode type) is a standard that defines the
printed symbol and how a device, such as a barcode scanner,
reads and decodes the printed symbol.
If an industry standard has already been established for
the intended implementation, the standard should be implemented.
If a standard does not exist for the chosen implementation,
several symbologies are available
to choose from.
Industry standards are usually established when multiple
parties or companies are involved in the ID process. The standard
is not necessarily the same as the barcode symbology. Barcode
standards define how to use the barcode symbology in a particular
situation. For example, the two standards to
ISBN barcodes for books and
generate ISSN barcodes for periodicals both use EAN-13 to
encode data into the barcode, but have different methods depending
on the specific ISBN & ISSN standards.
The chart below
includes a few established barcode standards and what they are
Established Barcode Standards:
* Beginning January 1, 2010,
GS1 DataBar may be used in place of all UPC and EAN barcode
types for POS.
IDAutomation also offers a
list of several popular barcode symbologies at the
barcode FAQ site and
how to identify the various symbologies.
IDAutomation offers several
Application Integration Guides that suggest one or more
options for integrating barcodes. The integration options should
be examined to determine whether to implement components, applications
or barcode fonts for printing. A few of the
Barcode Integration Guides offered include the following:
Once it is determined which product to use for the printing
of barcodes, the following suggestions may help in selecting
the barcode symbology:
for printing a certain number of characters, the following is suggested:
- When encoding uppercase and/or lowercase letters, numbers,
punctuation, any letter or symbol appearing on the standard
U.S. keyboard and lower
functions such as returns and tabs, up to about 40 digits,
All of IDAutomation's
support Code 128 as the default barcode type.
- When encoding several lines of data of any type over
40 characters, it is suggested to use the
Data Matrix barcodes.
using Barcode Fonts, the following is suggested:
- When encoding only numbers, up to about 30 digits, choose
Barcode Fonts. Codabar is the most dense, self-checking
- When encoding uppercase letters, numbers and these symbols
(- . $ / + %), up to about 20 digits, choose
39 Barcode Fonts. Code 39 is also a dense self-checking
(easy-to-use) alpha-numeric symbology.
- When it is necessary to encode uppercase and lowercase
letters, numbers, punctuation and ASCII functions such as
returns and tabs, up to about 40 digits, use
128 Barcode Fonts or the
- When encoding any data of any type over 40 characters,
Data Matrix barcodes.
When barcodes are sent via fax
machine or are used in a low-resolution environment, the following
evaluating several popular barcodes, the
Data Matrix barcode is the most dependable in a faxing
environment. Data Matrix is one of the smallest and most
dependable barcode symbologies. Compared to other barcode
types, Data Matrix is approximately 30 times smaller than
a Code 39 barcode representing the same data. This comparison
may be seen visually in the
Barcode Symbology Evaluation and Test Sheet.
- If the DataMatrix barcode cannot be implemented, it
is suggested to print the chosen barcode at the largest
X Dimension (or size) as possible, which will usually allow
the symbol to be read by a scanner.
- When printing to thermal 203 DPI printers, special care
must be taken to create accurate barcodes. Several knowledge
base articles exist for the proper use of thermal printers:
Applications are used, the following is suggested:
- To create barcode images individually, save the images
to a file or easily paste barcodes into other Windows applications,
Image Generator. This application is commonly used to
create barcode image files for PhotoShop, Paint Shop Pro,
Quark, CorelDraw, Word and other word processor and graphic
applications where a single image can be printed several
times without change.
- To print barcode labels dynamically from a database
or list with a label design application compatible with
Windows, consider IDAutomation's
When encoding photos, arrays, binary data,
Unicode, international or double-byte characters, the following
A two-dimensional symbology (2D barcode) such
as the PDF417 or Data Matrix barcode should be used to encode
this type of data. 2D barcodes encode this type of data when
the encoding mode is set to BASE256 or BINARY,
which encodes all data, byte-by-byte. When scanning the data,
the barcode scanner must be able to read all 256 bits of each
byte. This usually means using the serial interface option (data
bits have to be 8N) on the scanner, serial emulation over USB
or another type of connection that allows all 256 bits of each
byte to be transferred to the necessary application. Normally,
keyboard wedge and USB barcode scanners (that emulate a keyboard)
do not support extended characters above
128, and they only read characters that are actually on the
keyboard. The scanner manual or vendor may need to be consulted
for this type of implementation. Alternatively, the data may
be converted to Base64 when encoded in the barcode and then
back again when read. However, this requires additional programming
and will create a symbol that is about four times larger then
it would be with BASE256 or BINARY encoding.
When creating PDF documents,
the following is suggested:
IDAutomation barcode fonts may be used to integrate barcodes
into PDF documents, thus creating virus-free portable data files
that can be viewed on all operating systems with a PDF viewer.
The fonts have been tested and work with the following PDF conversion
Distiller Server works well with all of IDAutomation's
MICR, OCR and barcode fonts including symbol-encoded fonts.
Crystal Reports version 9 and above can create PDF documents
- PDFLib is a library
for generating PDF "on the fly" for programmers only. Runs
on Mac, Windows and several Unix platforms in addition to
EBCDIC-based platforms, such as IBM eServer iSeries 400
and zSeries S/390. PDFlib is especially well-suited for
generating PDF on a Web server. PDFlib can generate PDF
data directly in memory (instead of on file), resulting
in better performance and avoiding the need for temporary
files. This product was implemented by a client using IDAutomation's
PostScript Interleaved 2 of 5 Barcode Fonts with Redhat
Machine is a simple print driver that permits the creation
of a PDF document from any printable source. Version 6.2
supports printing the barcode font at small point sizes.
One of the most common tools for reading barcodes is the
recommended and sold by IDAutomation all have built-in decoders
that can read several different barcode symbologies. There are
a few low-priced scanners on the market, but they require complicated
decoders. In the long run, after ordering and programming a
decoder, more time will be spent using the decoder than if ordering
a scanner with a built-in decoder.
Most of the barcode
sold by IDAutomation receive their power from the PC keyboard
USB port so no external power supply is required. When a
barcode is scanned, the data is sent to the PC as if typed on
the keyboard. To learn more about scanning barcodes, review
how to scan
barcode data into applications.
Most barcode scanners can read common linear symbologies
such as Code 39, UPC, EAN, Code 128 and Codabar by default.
Some scanner manufacturers’ ship new barcode scanners with most
symbologies disabled, therefore, if a particular barcode cannot
be read, make sure it is enabled in the scanner's firmware.
Not all scanners read barcodes that are printed at small X dimensions
(the x dimension is the width of the narrow bar in the code,)
so it is advisable to check the barcode scanner manual to make
sure the scanner can read the small X dimensions.
IDAutomation Plug 'n Play USB Barcode Scanner performs similar to
a laser scanner and reads very small barcodes. Barcodes of 4
to 32 mils in size and up to 4.2" in width are easily read from
a distance of 4 to 8 inches with this scanner.
Many situations may exist where the space a barcode occupies
becomes a concern. The barcodes below are all encoding the same
data of "BARCODE12345678" with the same narrow bar width
or X dimension of .03CM or 12 mils. When creating small barcodes,
the scanner must also be able to dependably read them. Some
barcode scanners also read different symbologies better at different
sizes. For example, the
Laser Barcode Scanner dependably reads the
Barcode Font when printed as small as 6 points, but only
Barcode Font when printed at 8 points. However, the
IDAutomation Plug 'n Play USB Barcode Scanner reads both
Code 128 and Code 39 at 6 points and above. The barcodes below
may be printed from IDAutomation’s
Symbology Test Sheet for testing
As seen in the examples above, the Data Matrix barcode is
the most compact of the symbologies evaluated. However, it requires
a 2D Barcode
Imager or Image Reader to read the symbol. Several Imagers
can easily read small symbols, such as the
Barcode Imager which can read Data Matrix barcodes printed
Matrix Font as small as 2.5 points, which is an X dimension
of about .02CM or 8 mils. Data Matrix is also one of the
most accurate barcode symbologies.
The accuracy and amount of misreads of several different
barcode symbologies were evaluated in a study at
University Center for Automatic Identification. Studies
indicate that a well-trained data entry operator will usually
make a data entry error once every 300 keystrokes. Therefore,
implementing even the least accurate barcode symbology is a
huge step forward to increasing production and reducing data
||1 error in 10.5 million
||1 error in 612.9 million
||1 error in 10.5 million
||1 error in 612.4 million
||1 error in 2.8 million
||1 error in 37 million
||1 error in 1.7 million
||1 error in 4.5 million
||1 error in 394 thousand
||1 error in 800 thousand
Conversion Table & Specifications
Specifications are provided by many types of barcode implementations.
In some cases, the specifications of the barcode sizing parameters
are given in inches, but need to be calculated in CM (centimeters)
in the barcode tool. To convert inches to CM, multiply the value
in inches by 2.54. To convert mils to CM, multiply the MILS
(1 mil equals .001 inches) value by .00254.
Below is a chart that contains many common barcode dimensions:
More information about barcoding and "Frequently Asked Questions"
(FAQ) may be obtained from these sources:
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