Code 39

What is Code 39?

An alphanumeric barcode symbology (HIBC compliant).

The classic barcode type is Code 39 (also known as Code 3 of 9), which consists of 9 bars and spaces; three of which are wide and the other six narrow. In Code 39, 3 out of a total of 9 bars and spaces are wide (hence the name Code 3 of 9).

If you wanted to print the barcode ABCD, you would have to start and end it with a special start/stop character – for Code 39, the asterisk (*) is used for this purpose. So to print the barcode ABCD, you would need to enter it as *ABCD*. There should be a white quiet zone of at least 6.5 mm to the left and right of the code, so that it is easier for the reader to recognise where the barcode begins and ends.

Other barcode types are constructed in a similar way. UPC/EAN barcodes have four widths of bars and spaces, as does Code 128. Code 39 can represent 43 characters (0-9, 26 letters, 7 special characters). Each character is represented by a ‘3’ made up of ‘9’ bar combinations, consisting of two different bar widths.

Barcodes without a check digit (e.g. Code 39, Code 93, Codabar and 2 of 5 industry) can be entered directly into the target application and then formatted with the corresponding (barcode) font. For barcodes with interleaving or check digits, there is a separate programme that calculates the same. The barcodes calculated in this way are then inserted into the target application via the clipboard.