In this article we go over some of the rules for resizing and incorporating your barcode into your packaging design whilst still maintaining scannability. Learn what sizes can be used and which colour combinations will be scannable – that’s right, you don’t need to stick to black and white, and there’s no reason you can’t throw in a unique touch as well…
Dimension and sizing:
The most basic rule of thumb that SA Barcodes suggests is to print your barcode image at a minimum of 80% the original size, or up to 200% of original size if you wish. You can reduce the size to 75% but you will then need to check an initial print of your packaging before commencing the final print run – it is also suggested that you make sure to use a thermal printer if at all possible. This is due to the fact that resizing a jpeg image can cause the barcode to become pixelated or acquire grey pixels next to the solid black lines in a process which is known as anti-aliasing. This naturally reduces the integrity of the barcode data and limits the ability of the scanner to read the barcode correctly. Most modern scanners do have inbuilt error-correcting facilities, however erring on the side of caution is always advisable, particularly if you plan on supplying smaller retailers who may be using older technology.
Other basic rules for applying barcodes to your packaging as suggested by GS1 UK include the following:
- Barcodes must be located in the same location if you have many similarly shaped products or packaging
- The barcode must be placed no closer than 8mm to a packaging fold or seam
- If packaging is rounded the barcode needs to be appear on the surface which is most consistently curved (we would advise you verify that the code scans in this case as well)
- In the case which separately barcoded items are packaged in a container unit (for example if you are selling individual beverage cans as well as a six-pack option) – the unit barcodes must not be visible through the outer packaging
- If the object to be barcoded is cylindrical (such as a pen or marker) then the barcode needs to be aligned vertically in a ‘ladder orientation’ on the object
Printed image resolution is measured in DPI – or Dot Per Inch scaling, which indicates the number of pixels are printed onto each inch of the packaging material. The default value on most normal printers is 72 – however a minimum of 300 dpi is suggested for the printing of barcodes, with the ideal being 600 dpi or more. Whilst two images may appear identical on screen – an image printed at a lower resolution will actually print smaller on paper and have a lower quality then a high resolution image.
Remember that in the case of barcodes width is far more important than height, because the laser of a barcode scanner measures the width of the vertical bars and the spaces between them to convert the image into a binary format which the retailer’s inventory system can convert to call up the product information and pricing. The barcode packages which SA Barcodes sends contain barcode images at the standard or nominal barcode size and in high resolution – so if you use our images unchanged you will not run into scanning problems.
Spacing of your barcode on packaging:
It is also important to note that your designer must allow sufficient blank space on either side of the barcode known as the ‘quiet zone’ or ‘light margin’. This blank area before and after the first and last bars of the barcode allows the scanner to recognise where the code begins and ends.
Below is an example of a standard EAN barcode at 100% magnification. As you can see the recommended left and right quiet zones are 3.63mm and 2.31mm respectively at this size.
We have compiled a table of the ISO-approved standards for a range of magnifications below, where ‘bar height’ indicates the height of the bars only – i.e. not including the human readable numerals below the barcode; and ‘width’ meaning the width of the bars and spaces excluding the quiet zones on each side.
Printing a colour barcode:
It is possible to print your barcode in a colour combination that matches your product or packaging as long as the level of contrast between the bars and background is high enough, generally 63% or higher. However, remember that because the light emitted by a barcode scanner is red, only certain colour combinations are possible. Contrast is measured in PCS – or Print Contrast Signals. This is the value of the change in reflectivity between the light and dark spaces of the barcode which the scanner will read. As results can differ based on the type of material and printing method used, it is advisable to run a PCS test prior to commencing the final print run. The following general guidelines apply when choosing a combination:
- Barcode bars must be darker than the background colour
- If your packaging is transparent or semi-transparent such as in plastic packaging, a solid background colour must be applied to the outer packaging in the area where the barcode appears. You cannot use the colour of the units contained within the external wrapping as the background colour
- The best high-contrast combinations contain bars which are high in black, blue or green content (the ‘cold’ colours of the spectrum) printed on a background which contains warm colours such as yellow, white, orange or red
- Bar colours must be ‘pure’ colours rather than the standard four-colour CMYK print combinations
For designers, a very comprehensive PCS and reflectance value table is available on http://www.barcode-us.com/sites/default/files/bcgcolorguide.pdf
Here are some examples of scannable colour combinations:
The following combinations are NOT scannable and must be avoided:
It is also worth noting that you should avoid using metallic colours as they reflect light differently.
If you have adhered to all the rules above then there’s no reason you can’t take creativity one step further and attempt a ‘vanity’ barcode – such as the one above by Dion Label Printing – to give your product that extra special something! As long as the central section of the barcode maintains the correct spacing between bars, the top and bottom edges of the barcode lines can be extended to create a unique design whilst still remaining fully scannable. Here are a few more examples to inspire you!