What are Codablock Barcodes?

What do you mean by Codablock Barcodes

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Codablock barcodes are a 2D symbology that offers high-density data storage. Developed by stacking multiple Code 39 or Code 128 barcode symbols, Codablock barcodes provide an innovative solution for encoding large amounts of data in a compact format.

In this blog post, we will delve into the world of Codablock barcodes, exploring their types, features, and benefits.

What is a Codablock Barcode?- A Detailed Explanation

Codablock Barcode

Codablock barcodes were introduced in 1989 by Heinrich Oehlmann in a German company called Identcode Systeme GmbH. The name “Codablock” was derived from the block shape formed by the barcode’s multiple rows.

Codablock symbologies use a combination of stacked rows of 1D barcodes (Code 39 barcodes and Code 128 barcodes) to create a more efficient and secure system for encoding and decoding data. They offer similar benefits to 2D barcodes like QR codes, such as the ability to use space more efficiently and extra check characters to verify the message content. To learn more about QR codes, refer to our article on what is a QR code.

Codablock barcodes can carry a large amount of data in a small space. These barcodes have widespread use in healthcare, facilitating patient identification, managing medical records, and tracking prescriptions.

Codablock barcodes have been replaced by more efficient Data Matrix barcodes thanks to barcode technology advancements. Data Matrix barcodes offer a more significant data capacity, feature advanced error correction, and are more easily scanned with modern barcode scanners and mobile devices.

Check out our article on what are DataMatrix barcodes to learn more about them

What is the Purpose of Codablock Barcodes?

Five benefits of Codablock Barcode

Codablock stacked symbology offer several advantages and features that make them suitable for a range of industries.

One of the main purposes of the Codablock barcode family is to enable high-density data storage. By stacking multiple rows of data, Codablock barcodes can store a large amount of information within a compact space.

Another purpose of the Codablock barcode is to provide flexibility in barcode design. Codablock barcodes can be customised to meet specific requirements by adjusting their height, width, and density options.

The Codablock barcode incorporates features to enhance security and error detection. They have additional checksum digits that improve the accuracy of the barcode by verifying data integrity during scanning.

Codablock barcodes also have a numeric compression capability. This numeric compression capability allows to encode blocks of numbers using only the half of the usual space.

How to Recognise Codablock Barcodes?

Identifying Codablock barcodes is relatively straightforward. Codablock barcodes have a distinct appearance that differentiates them from other barcode symbologies.

Codablock barcodes have a block-like shape that is formed by their multi-row, stacked, lined structure. The rows of the barcode are composed of either Code 39 or Code 128 symbologies. This unique arrangement and structure make Codablock barcodes easily recognisable.

Check out our article on Code 39 vs Code 128 barcodes to discover the differences between these two barcode types.

Three points on how to identify codablock barcodes

Types of Codablock Barcodes

Three types of Codablock Barcode

The Codablock barcode family includes three types of barcodes, namely.

  • Codablock A
  • Codablock F
  • Codablock 256

Codablock A

The first variant of Codablock barcodes developed between 1989 and 1995 is called Codablock A. It was created by stacking multiple Code 39 barcodes. However, Codablock A was not extensively used due to the limitations of the Code 39 barcode.

Codablock A is a compact barcode that can store a moderate amount of data. It contains 2 to 22 lines, each with 1 to 61 characters. The Codablock A barcode symbology can hold a maximum of 1,340 data characters.

Codablock A uses a checksum calculation method known as Modulo 43 across the entire code block to maintain accuracy.

Codablock F

Codablock F is the current version of the Codablock barcode family based on the Code 128 barcode symbology. It is designed to store and encode a larger amount of data compared to Codablock A.

The Codablock F barcode is made up of multiple stacked Code 128 barcodes. It can have 2 to 44 barcode lines, each with 4 to 62 data characters. Codablock F barcodes can store up to 2,725 characters of data.

An important feature of Codablock F is its ability to encode the full 256 ASCII character set, providing a wide range of character support.

However, it is worth noting that Codablock F is considered a historical standard and is not recommended for use in new applications. Codablock F barcodes are less dense than other 2D barcodes because they are a modified 1D Code 128 barcode version.

Codablock 256

The Codablock 256 barcode was developed as an internal standard developed by ICS Identcode-Systeme GmbH. It is made up of Code 128 barcodes that are stacked together.

The Codablock barcode can encode all 256 symbols of the ASCII character set, including the FNC4 character. Like Codablock F, Codablock 256 has a maximum data capacity of 2,725 characters.

However, it is important to note that Codablock 256 is not standardised internationally and has remained an internal development. Codablock 256 is no longer extensively used and has been supplanted by more widely used barcode formats.

Anatomy of Codablock Barcodes

Codablock A

Detailed anatomy of Codablock A barcode

Codablock A codes are continuous and variable-length, allowing for flexible data storage.

Each row of the Codablock A symbol contains.

  • Leading/trailing quiet zones
  • Start character
  • Data portion
  • Stop character

The structure of a Codablock A symbol consists of 1 to 22 rows, each containing a start and stop bar that extends the height of the symbol.

To indicate each row, a two-character row indicator is used. The last row of the symbol also includes an optional Modulo 43 check digit for enhanced error detection. 

Refer to our article on what is a Code 39 barcode to learn more about Code 39 barcode and its structure.

Codablock F

Seven points on structure of Codablock F barcode

The Codablock F symbol comprises the following elements per row.

  • Leading and trailing quiet zones
  • Start and stop character
  • Character subset selector
  • Row indicator
  • Symbol characters that represent data
  • Row check character

A Codablock F barcode is made up of rows of Code 128 symbols. Each symbol can have 2 to 44 rows. The Codablock F barcode contains extra information in each row, such as the row number or row checksum, to ensure the decoded information is in the correct order.

Codablock F can encode the entire Code 128 character sets, providing a comprehensive range of characters for data representation.

Refer to our article on what is a Code 128 barcode to learn more about Code 128 barcode and its structure.

Codablock 256

List of seven points of structure of codablock 256 barcode

The Codablock 256 has the same structure as the Codablock F barcode.

How to Get a Codablock Barcode?

The Codablock barcodes are available for public use without requiring a license or permission. Anyone can generate them using free online tools like Codablock Code Generator or specialised software like Seagull Scientific’s BarTender Software.

Here’s a step-by-step process on how to generate different types of Codablock barcodes.

  1. Determine the type of Codablock barcode you want to generate. There are different variants, such as Codablock A, Codablock F, and Codablock 256.
  2. Research and select a reliable barcode generator or online tool that supports Codablock barcodes. Ensure that the chosen tool supports the specific variant of the Codablock barcode you want to create.
  3. Launch the barcode generator tool and enter the desired data or information that you want to encode into the Codablock barcode.
  4. Customise the appearance and settings of the barcode. Adjust the size, density, and other parameters according to your requirements.
  5. Generate the barcode by clicking the “Generate” or “Create” button within the barcode generator tool.
  6. Verify the generated image of the Codablock barcode to ensure it accurately represents the encoded data.
  7. Use the generated barcode image in your desired applications or print it on labels, packaging, or other materials as needed.

Remember to test the readability of the printed or displayed Codablock barcode using a barcode scanner or a barcode scanning app to ensure its functionality.

At Triton, we offer a range of reliable barcode scanners from top brands such as Zebra and Honeywell. Our inventory stocks different barcode scanner models, including general scanners, rugged scanners, USB scanners, 2D scanners, wireless scanners, Bluetooth scanners and fixed scanners and sensors.

When it comes to Codablock code generation, there are many options available online. Switching to free barcode generators is tempting to save money, but it’s important to note that these free tools have limitations. These limitations include limited customisation options, no security features, and limited technical support.

As a result, investing in a reliable barcode generator or specialised software like BarTender can help you generate Codablock barcodes quickly and accurately.

Seagull Scientific’s BarTender Software helps users create attractive labels with impressive graphics and text and simplifies the entire labelling process by enabling automation and management. The software can even include RFID tags, making it a revolutionary tool in label design, management and printing software.

At Triton, we provide various BarTender Software editions that cater to various business requirements. We offer Starter Edition, Professional Edition, Automation Edition, and Enterprise Edition, along with BarTender Cloud. Rest assured that you can enjoy the best prices for these top-quality software products and transform your label printing experience with us.

To learn more about Seagull Scientific BarTender Software, contact us via the live chat widget below or fill out a form here.

How to Design Codablock Barcodes?

Five points describing how to design codablock barcodes

Properly designing Codablock barcodes is essential to ensure their readability and accuracy.

Here is a basic guide to help you design Codablock barcodes.

  1. Depending on the Codablock type, determine the number of rows needed to accommodate your data. Codablock A can have 1 to 22 rows, while Codablock F can have 2 to 44 rows
  2. Assign two-character row indicators to each row of the Codablock barcode
  3. Include start and stop bar groups at the beginning and end of the barcode
  4. Consider incorporating error detection mechanisms to enhance barcode reliability. Codablock A employs a Modulo 43 check digit in the last row, while Codablock F utilises Code 128’s error correction capabilities
  5. Adjust the print density to ensure that the Codablock barcode is clear and easily scannable. Test different print densities to find the optimal balance between size and readability

How to Print Codablock Barcodes?

List of five printing rules of Codablock barcode

To ensure Codablock codes are scanned correctly, it’s important to consider the printing quality. Here are some best practices for printing Codablock barcodes.

  1. Use high-quality barcode printers: Invest in a reliable printer that can produce clear and accurate Codablock barcodes.
  2. Select the appropriate barcode size: Choose the size of the Codablock barcode that suits your specific application.
  3. Use a clean and clear background: Ensure that the background of the barcode is clean and free from any patterns, textures, or colours that may interfere with scanning.
  4. Maintain proper quiet zones: Leave sufficient empty space on all four sides of the barcode.
  5. Verify barcode readability: Always test the printed Codablock barcode using a barcode reader to ensure readability. Verify that the encoded data can be accurately decoded and the information matches the intended content.

You can print Codablock codes using different printer technologies like inkjet, laser, and thermal printing. However, thermal printing is the most recommended option since it provides high-quality results and guarantees a longer lifespan for the code.

Thermal printing is a method of printing that uses heat to create a digital image on various printing materials. These printers have a thermal printhead that produces heat to activate the dye or ribbon and transfer it onto the printing medium.

At Triton, we know how crucial it is for your business to have dependable thermal printing solutions. That’s why we provide a wide variety of exceptional thermal printers from major brands such as Zebra, Honeywell, TSC, and coloured label printers from OKI. Our collection only includes the most precise, efficient, and sturdy printers to suit any printing needs you may have.

Our inventory features a variety of printers, including desktop label printers, industrial label printers, direct thermal printers, thermal transfer printers and barcode label printers, ensuring that we have something to cater to every printing task, no matter how complex.

We also have a range of print consumables, including thermal labels, thermal carton labels, thermal carcase tags, thermal inserts, and thermal transfer ribbons, so you can easily replenish your printer supplies in no time.

So why wait? Contact us today via the live chat widget below, and let us provide you with the best printing solutions for your business.


In conclusion, Codablock barcodes are a powerful and versatile tool for encoding and managing data. Their use of stacked rows of 1D barcodes and error-correcting codes, combined with their security features and versatility, make them an ideal choice for various industries and applications.

Codablock barcodes were used in areas such as healthcare and libraries. However, with the emergence of more advanced barcode symbologies, Codabar has become less prevalent in recent years.

We hope this article has helped you understand what Codablock barcodes are, how they work, and their various applications.

If you need any assistance with barcode printing solutions, don’t hesitate to contact us at Triton. Our team of experienced professionals is here to help you!

We look forward to hearing from you soon!

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