Barcode Basics >
Different Types of
Barcodes > PDF-417
PDF-417 is a two-dimensional barcode which can store up to about
1,800 printable ASCII characters or 1,100 binary characters per symbol. The symbol is
rectangular; the shape of the symbol can be adjusted to some extent by setting the width
and allowing the height to grow with the data. It is also possible to break large amounts
of data into several PDF-417 symbols which are logically linked. There is no theoretical
limit on the amount of data that can be stored in a group of PDF-417 symbols.
The capacity of PDF-417 can be helpful in applications where the data must travel with
the labeled item, where a host database is not always available for quick look-up. PDF-417
is being used for hazardous materials labeling; storing technical specifications and
calibration data on electronic instruments; encoding fingerprints and photographs on the
backs of drivers' licenses.
The maximum data density is determined by the smallest elements which can be reliably
printed and scanned. Using the smallest recommended element size of 0.0075 inch wide and
0.010 inch high, the maximum data density in the binary mode is 686 bytes per square inch
(106.2 bytes per square centimeter). In the printable ASCII mode the density is 1,144
characters per square inch (177.2 characters per square centimeter).
PDF-417 symbols require a 2-D scanner; or a standard CCD or laser scanner and special
decoding software (a wand scanner will not work). A number of scanners are on the market
using both laser and CCD camera technologies. PDF-417 symbols can be printed using most
professional-grade thermal transfer label printers on the market. The Barcode Software
Center carries several label design and printing programs that can create PDF-417 symbols;
we also have function libraries for programmers, programs for creating master artwork, and
add-in hardware modules for Hewlett-Packard printers.