Invented by Norman Joseph Woodland and developed by George Laurer in the 1970s, the barcode was developed as a solution for grocery shops. It was designed to eliminate mounting costs and reduce the labour-intensive task of putting price tags on products.

Fast forward to 2020 and the barcode has developed into several varying types to accommodate its success and adaption into daily life. Barcode and security label specialist, inotec UK, manufactures, supplies and installs barcode and labelling solutions for a range of industries.

When approaching a barcode label specialist company like inotec UK, it is essential to correctly identify which barcode system is needed or currently used. If a customer unknowingly selects the wrong barcode system, it can lead to the whole labelling system being unreadable by the scanning or WMS system installed.

To simplify the process and help customers identify the right solution, inotec has put together a guide for the three most common barcode types.

Barcode Symbology – How to recognise barcodes using symbology

If you are in doubt as to which barcode system your facility and products use or need, you can often tell just by looking at the barcode’s symbology. You should ignore the first few guard bars on barcodes as they determine the start and finish in case the code is read upside down. If the barcode is scanned upside down, the reader will read the barcode in reverse.

  • Interleaved 2 from 5 Barcode (ITF) – Following the guard bars, you will see that 2 in every 5 bars are thick. There will also be 2 wide spaces in every 5 spaces. Both the five lines and wide interleaved spaces represent the digits 1, 2, 4, 7 and 0. The lines and spaces are interleaved and read by a scanner to equate to any number up to 9.
  • Code 39 Barcode – Following the guard bars again, on a Code 39 barcode, 2 bars in every 5 are thick. In contrast to Interleaved 2 from 5 barcodes, only one space per 5 bars will be wide. You may also see interspersed sets of 5 thin bars together with 2 wide gaps. This set of 5 thin bars reads symbols only.
  • Code 128 Barcode – The Code 128 barcode is a high-density barcode using multi-width lines and multi-width spaces and therefore can be quickly distinguished from Interleaved 2 from 5 and Code 39 barcodes.

Distinguishing and understanding the difference between the three barcode types

  1. Interleaved 2 from 5 Barcode (ITF)
    Interleaved 2 from 5 is a numeric-only barcode which was first developed in 1968. Its format is used to encode pairs of numbers into a self-checking, high-density barcode format. This system reads both the bars and their ‘interleaved’ spaces. Thus reducing the length of the overall code. The five lines represent the digits 1, 2, 4, 7 and 0. So, for example, the second and fourth digits would equate to ‘9’ (2+7) and the first and fifth digits would equate to ‘1’ (1+0). The second digit in the pair is read within the spaces – there are two wide spaces in the first five lines. Both the lines and the spaces are interleaved to be read by the scanner. This type of barcode is only suitable for coding with numbers 0-9 and therefore is one of the least commonly used types of barcode.
  2. Code 39 Barcode
    The Code 39 barcode introduces far more variation by allowing upper-case alphabet letters A-Z, the space character and select symbols in addition to numbers for alphanumeric codes. This combination makes them ideal for identifying warehouse items such as racking which often requires a combination of letters and numbers for building letters, aisle letters, pallet position numbers and racking level letters or numbers. It uses the same principles as the ITF barcode reading 2 wide bars from 5, however, the spaces do not represent a character as with ITF codes. There will only be one wide space in every 5 bars. This space determines which set of digits the 5 bars will represent. There are 4 possible wide space locations within 5 bars, 1, 2, 3 and 4. The first location will read the bars as U-Z, the second location will read the bars as 1-9, the third location as A-J and the fourth location as K-T. Characters including spaces, $, /, +, and % are represented by 5 x narrow bars with 2 x wide gaps. A long sequence code will result in a long barcode as it reflects the length of the code. Code 39 is a common type of barcode as it is ideal for use on labels for name badges, inventory and industrial applications.
  3. Code 128 Barcode

Code 128 is a high-density barcode which reduces the code length that would be required compared to Code 39 barcodes. Code 128 barcodes also introduce additional symbols. They can encode all 128 characters of ASCII, hence the 128 reference in the name. This is one of the most popular types of barcode and is widely used in applications where a relatively large amount of data must be encoded into a relatively small amount of space. The barcode introduces different width bars and gaps. This ultimately allows for more information to be condensed into a smaller barcode.The popular 128 barcode replaces Code 39 and Interleaved 2 from 5 barcodes as a more compact and flexible code for warehouse and distribution facilities due to its continuous, self-checking bidirectional features. It is also commonly used in the health industry, blood banking and electronics manufacture.

The importance of choosing high-quality barcode labels

Once you understand which type of barcode system your warehouse uses and needs, the next step is to choose a reputable supplier to ensure your labels are printed using high-quality digital print. It is essential your supplier uses digital print to ensure barcode printing is crystal clear.

In production facilities and warehouses, labels often become dirty due to everyday wear and tear as well as general environmental factors such as dust. If dirt was to get stuck between the lines on the barcode labels, it can cause the read of the barcode to fail. Due to the different patterns of the barcode types, the barcode reader needs to be able to recognise the gaps within the barcode. Therefore any dirt or scratches can cause the misread of barcode labels creating many issues.

Furthermore barcodes can become easily scratched during use and movement. This can cause issues such as misread or unreadable barcodes. Having to manually type in the barcode into scanning systems can be lengthy and also allows room for human error and typos.

To protect barcodes from scratches and dirt, inotec UK recommends laminating barcode labels. This extends the life span of barcode labels by protecting them from scratches and allows them to be easily cleaned.

As Europe’s leading warehouse solutions and barcode label supplier, inotec recognises that despite being the least costly part of any installation, incorrect or failing barcode labels are the most common reasons for investments to fail. For example, in warehouses, barcode labels are a small part of the larger system made up of barcode scanners, WMS systems, racking and trucks yet an incorrect barcode label installation will prevent the whole system from working. It is, therefore, essential to get the labelling system correct.

If you would like to book a free consultation or speak to the sales team of one of the UK’s most trusted and experienced barcode label supplier, please contact inotec UK on 01482 654466 or email for more information.