Some barcode types, or symbologies, encode only numbers while others encode letters and numbers. Other barcode types can actually encode files, pictures and other binary data. Here is a basic breakdown of a few barcode types and what they encode:
|Barcode symbology||Types of data encoded|
|Code 39||Numbers and upper case letters with a few symbols|
|Code 128||All numbers, letters and punctuation plus ASCII 0 to 127|
|Data Matrix||All numbers, letters and punctuation, ASCII 0 to 127 plus files and bytes.|
|Interleaved 2 of 5||Numbers only|
|MSI Code||Numbers only|
|PDF417||All numbers, letters and punctuation, ASCII 0 to 127 plus files and bytes.|
Recommendations for barcoding:
If the intended use of the barcode fonts is for printing, check the type of data to encode:
- Only numbers, up to about 20 digits, choose Codabar or Interleaved 2 of 5. Codabar is the densest self-checking symbology. ITF is a numeric-only barcode used for encoding pairs of numbers in a high-density barcode format.
- Only uppercase letters, numbers and these symbols (- . $ / + %), up to about 15 digits, choose Code 39. Code 39 is the densest self-checking alpha-numeric barcode type.
- Uppercase and lowercase letters, numbers, punctuation, any letter or symbol appearing on the US 101 key keyboard and lower ASCII functions such as returns and tabs, up to about 20-30 digits, use Code 128.
- Several lines of data of any type over 20 digits, use PDF417, Aztec, QR-Code or Data Matrix.
If the intended use is a barcode component or label printing application, check the type of data to encode:
- Uppercase or lowercase letters, numbers, punctuation, any letter or symbol appearing on the US 101-key keyboard and lower ASCII functions such as returns and tabs, up to about 20-30 digits, use Code 128, which is in the Linear ActiveX Control, Label Printing Programs, Streaming components for IIS, .NET Forms Controls, ASP.NET Server Controls or the Java Bar Code Products.
- Several lines of data of any type over 20 digits, use PDF417, Aztec, QR Code or Data Matrix, which is in the ActiveX Control, .NET Barcode Forms Controls,ASP.NET Server Controls, 2D Barcode Fonts, Label Printing Barcode Programs, Streaming Server Component for IIS or the Java Products.
In a study at Ohio University, several different bar code symbologies were tested to determine their accuracy and are listed below. Keep in mind that a well-trained data entry operator will usually make a data entry error once every 300 keystrokes. Therefore, even implementing the least accurate symbology is a huge step forward to increase production and reduce data entry errors. The most inaccurate symbology (UPC) is used in the retail industry.
|Barcode Type||Worst Case Accuracy||Best Case Accuracy|
|Data Matrix||1 error in 10.5 million||1 error in 612.9 million|
|PDF417||1 error in 10.5 million||1 error in 612.4 million|
|Code 128||1 error in 2.8 million||1 error in 37 million|
|Code 39||1 error in 1.7 million||1 error in 4.5 million|
|UPC||1 error in 394 thousand||1 error in 800 thousand|