Barcode FAQ

  • What are barcode symbologies?


    Symbologies are different ways of representing data in bar and space patterns.  Some symbologies use only two different widths of bar and space while others use four.  Different symbols have been designed to meet different data encoding requirements, and some are designed to be readable when printed onto poor quality substrates.  The barcodes of the GS1 System are intended for use in open trade, while others such as Code 39 and Code 128 are available for sector-specific or in-house use.


    If you are not sure which barcode symbol you need, please ask us, and we will be happy to explain.


  • Where do I obtain my barcode number?

    If you are new to barcoding and need to create EAN-13, ITF-14 or GS1-128 barcodes for your products, you will first of all need to join a GS1 member organisation to obtain your GS1 company prefix.  For the UK, this is GS1 UK, and they will provide you with help about how to allocate numbers to identify your products.  If you want to barcode a book or a magazine, then Nielsen Book Services (the UK ISBN Agency) or the British Library (the UK ISSN Agency) will be the people to contact to obtain the correct numbers. If you are based outside the UK, search for GS1 (your country).


  • Can I have my barcodes produced at the size I choose?

    There are standard ranges of sizes for GS1 barcodes when used for particular applications, and the choice within these will be determined by your printing or production method.  The barcode may need to be slightly larger (or smaller) than you first thought to make sure that it is printable at a high quality and can be easily scanned.  We can help you determine the right size for your product and printing process.

  • What is a light margin or a quiet zone?

    Most barcodes require a clear area to the left and right of the bars which must not contain text or other images. These are known as the quiet zones, and they were previously known as light margins.  The size of these depends on the choice of barcode.  If these quiet zones are not wide enough, the barcode will not be scannable.

  • What is a digital image?

    A digital image of a barcode is one that can be incorporated into artwork design using dedicated software packages such as Adobe Illustrator.  They are created to be a particular size, and should not be manipulated to make them larger or smaller.

  • Why is the output resolution important when creating a digital image?

    Barcode images are very accurate master images that have been adjusted to match the printing process being used.  If the output device cannot resolve the dimensions required accurately, rounding errors will make some bars wider or narrower than intended.  For example, with a 1270 dpi output device, the bars it can create must be multiples of 1/1270 of an inch, or 1/50 mm.  This means the width of a bar can be adjusted by 20 microns, but no lesser dimension.  If the resolution is only 152.4 dpi (or 12 dpmm), each element has a width of 0.166 mm, and each bar width must be a multiple of this dimension.  It is simply not possible to produce a bar width of 0.20 mm, as the next largest size is 0.33 mm.


    The equipment will attempt to output the image, and it will introduce rounding errors that affect the accuracy of the printed image.  It is therefore very important to use a high resolution output device when imaging or printing barcodes and to select an appropriate size for the barcode to suit the output method and resolution

  • How long will it take to have a barcode created and sent to me?

    Most orders received by Axicon’s Barcode Bureau will be fulfilled within a few hours, so we will usually e-mail the barcode image to you (or your designer or printer) on the same day you ordered it.

  • Can the barcode be supplied in various formats?

    The best file format for a digital barcode is Encapsulated Postscript (EPS) because it is a vector graphic image which defines bar dimensions precisely. Bitmap file formats will be less accurate, depending on the resolution with which they have been made, and some bitmap formats approximate the image in what is known as lossy compressed formats. If a bitmap format has to be used for some reason then a high resolution TIFF image is probably the best choice.

  • How do I open the barcode image once it has been emailed to me?

    The barcode image cannot be opened using standard office software packages, and is intended to be used in a page layout program.  It should be forwarded to the designer or printer who will have an appropriate program.

  • Can I use any program to open the .eps file?

    The image carried in the .eps file should be placed into a page layout program such as Quark Xpress, Adobe InDesign or Adobe Illustrator as these programs will allow the vector graphic format to be preserved. Programs that are designed for modifying images, such as Photoshop, should be avoided.

  • Is the printing method and substrate important?

    Different printing methods and substrates will affect the original barcode image in different ways, particularly in the amount of ink spread that occurs which makes the bars wider. The colour of the ink used to print the bars and the colour of the substrate will also affect the readability of the symbol.  The bars must appear as black when read by a scanner that uses red light to read them.

  • My artwork has been printed but does not have a barcode, what should I do?

Barcode FAQ


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See also

Barcode images

Barcode colours

15000 series barcode verifiers

The Axicon 6500 series barcode verifier is designed to verify linear barcodes with a maximum width of 125 mm.

Acceptable colour combinations for printing barcodes

The Axicon 15000 series verifiers have been designed to read both two-dimensional and linear barcodes.

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Axicon Auto ID is a world leader in barcode verification, having developed and manufactured our own range of verifiers since 1989. Axicon barcode verifiers are used to measure the quality of linear and matrix barcodes, on all levels of product packaging.




+44 (0)1869 351155

+01 (434) 939 9647

Weston on the Green


OX25 3QP, UK

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