Creating Code 39 Barcodes

Code 39 (also known as Code 3 of 9, or Type 39) is one of the most popular and versatile alphanumeric barcodes used in inventory, automotive, healthcare, and defense industries. It is called "Code 3 of 9" because each character consists of 9 elements (5 bars and 4 spaces), of which 3 are wide and 6 are narrow.

Using iBarcoder makes generating, customizing, and printing perfect Code 39 barcodes fast and accurate.

What is Code 39?

• • Type: Alphanumeric (supports uppercase letters A–Z, numbers 0–9, and special characters like -, ., $, /,+, %, and space).
• • Self-Checking: Code 39 is self-checking, meaning standard verification algorithms are built-in, though a modulo 43 check digit is optional for enhanced security.
• • Start/Stop Character: Every Code 39 barcode must begin and end with an asterisk (*) character.

Step-by-Step: How to Generate Code 39 Barcodes

Creating a Code 39 barcode is quite easy when it is done using iBarcoder:

1. Select Code 39 Symbology:

Open iBarcoder and click the Barcode icon in the toolbar to add a new barcode object to your label canvas. In the Barcode Type dropdown menu within the Barcode Properties Panel, select Code 39.

2. Format Your Data:

Ensure your text string only contains supported characters:

• • Uppercase letters: A through Z.
• • Numbersg: 0 through 9.
• • Special characters: Space, -, ., $, /, +, %.

Navigate to the Barcode Properties on the right of the iBarcoder window, and enter your barcode data string into the 'Data' text field.

3. Customize Appearance & Dimensions:

Adjust the height, bar width (X-dimension), margins, and quiet zones under the Barcode Properties panel. You can also toggle human-readable text on or off, adjust the font style and color settings.

If you need that the text to contain the Code 39 start Stop characters, then set the Start/End Char attribute to ON under human readable text. This wrapa your text data with asterisks (*).

4. Print or Export:

Print your barcode directly to standard label sheets (such as Avery templates) using thermal, laser, or inkjet printers. Alternatively, export vector (PDF, EPS) or high-resolution raster (PNG, TIFF, JPEG) graphic files for packaging design.

Key Features for Code 39 Creation in iBarcoder

Feature	Description
Bulk Generation:	Import lists from .xlsx or .txt files to generate thousands of Code 39 barcodes at once.
Sequential Counter:	Automatically generate incremental Code 39 sequences using prefix, starting number, and step values.
Color Modes:	Switch between RGB and CMYK color spaces in iBarcoder Settings to prevent color conversion issues in professional print workflows.
Vector Export:	Output EPS and PDF files to guarantee sharp, 100% scannable print results.

Best Practices for Printing Code 39 Barcodes

• • Quiet Zones: Always leave a blank margin (at least 10 times the narrow bar width) on both the left and right sides of the barcode.
• • Size and Scaling: Ensure the barcode isn't printed too small for your scanner to read, especially if using thermal label printers.
• • Contrast: Use black bars on a clean white background. Avoid low-contrast color combinations.

Standard Code 39 only supports uppercase letters. If you need lowercase, you must use Code 39 Full Ascii, which maps ASCII pairs to represent lowercase letters and additional symbols.

Full ASCII Mode (128 characters): Represents lowercase letters, symbols, and control codes by pairing standard Code 39 characters with a prefix symbol ($, %, /, or +)

A check digit is optional for Code 39. However, for high-accuracy applications (like warehouse logistics or aerospace), enabling a modulo 43 check digit is strongly recommended.

Code 39 Mod 10 is an optional error-checking variant of the Code 39 barcode symbology that appends a single numeric check digit (0–9) to numeric-only data string. It uses a standard modulo 10 algorithm (similar to UPC, EAN, and Interleaved 2 of 5).