What is "bar code symbology"?
Symbology can be described as a computer language - the computer
translates the bars and spaces into Binary code. The binary code
is then translated into predetermined letters or numbers based
on the value of the binary code. There are a variety of different
bar code symbologies. Changing the width and spacing of the bars
and spaces within each individual bar code creates these different
symbologies. Some of the most common bar code symbologies are
Code 3 of 9 (or Code 39), UPC, Code 128, Codabar and Interleaved
2 of 5.
What is a quiet zone?
The quiet zone is the clear area at the beginning and end of a
bar code. This clear area keeps the scanner from picking up information
that does not pertain to the barcode you are scanning (ex. The
scanner may see a line that forms columns around the bar code
which may keep it from reading the bar code or give an improper
scan). Most clear areas are recommended to be at least 10x the
width of the narrowest bar or space used in the bar code. A simple
rule of thumb when designing a form or label with barcode would
be to leave ¼" or more of clear space.
Can a bar code contain alpha
characters?
Yes. Code 3 of 9 is among common bar code symbologies that allow
the user to use letters as well as numbers. This increases the
combination of codes that can be created or may allow prefixes
to be assigned to various offices/shipping locations, etc.
What is a check digit?
This is a number within the barcode, generally at the end, whose
value is used for the purpose of performing a mathematical check
to ensure the accuracy of the bar code.
How do my customers get
UPC codes for their products?
The Uniform Code Council in Dayton Ohio is the clearinghouse for
assigning these numbers. The contact information is as follows:
UCC
8163 Old Yankee Road, Suite J
Dayton, OH. 45458
513-435-3870
http://www.uc-council.org/
What is barcode density?
Space for bar codes is often at a premium. The density of the
barcode refers to how much space is required for the needed characters.
This is determined by the nominal width of the bars and spaces
that make up the code itself. The narrower the nominal width of
the bars and spaces, the higher the density of the bar code. As
a rule of thumb: Low density = 3 or 4 cpi; medium density = 5
to 7 cpi; high density = 8 or more cpi; referencing code 3 of
9. Certain printing methods, such as laser and thermal, allow
for higher density codes because they can create a narrower width
bar than impact printing systems. Also, some bar codes--such as
Code 128 and I-2 of 5--require less space than others.
What are some of the criteria
that should be considered when determining which method to be
used to print a barcode?
Many factors need to be considered, chief among these are size
and density required, durability needed, end use environment,
volume of bar codes to be supplied and whether or not multiple
plies are to be imaged.
What do the term's "picket
fence" and "ladder" have to do with barcode terminology?
These terms refer to the orientation of the barcode. Bar codes
that go from left to right are referred to as "picket fence" style.
Bar codes that appear vertically are known as "ladder" style.
The orientation is important in helping the manufacturer determine
the best way to produce the bar code needed.
What is first-read rate?
This term refers to the number of times a barcode scans correctly
on the first attempt. A low first-read rate may mean that the
application should be evaluated to determine if the symbology,
printing method and scanner used are suitable for the application.
What if I don't know what
bar code symbology my customer is using?
Ward/Kraft has scanning equipment that can be used to determine
the symbology of your customer’s bar code sample. Also,
a test bar code may be printed and sent to the customer for verification.
