07 Jul

Do you know your BWR?

We’ve recently had a couple of users of Barcode Basics (our mac barcode software) ask us what BWR is.

BWR stands for Bar Width Reduction. This allows you to reduce the width of each individual bar in your barcode by a certain amount. A common mistake is to specify a BWR as a minus number which in fact leads to an increase in bar width.

Of course, there are some rare occasions where you might need to increase bar width. However, remember that to reduce bar width, you need to have a positive BWR value.

Why do we use BWR?

The width of the bars in a bar code is important and needs to be precise to ensure they will scan properly. Depending on how you’re printing you bar code, you might find that the width of the bars increases when you print them. Think of how the ink spreads when you draw on tissue paper with a marker pen. This could result in the barcode not scanning properly.

This ink spread is especially common in commercial printing using a traditional printing press, rather than the type of printer you probably have on your desktop. So, to make sure the printed bars are the right width, we reduce the width of the bars in our code by using the appropriate BWR value.

How do I know what BWR value to use?

For most types of digital printing, including desktop laser printers you almost certainly don’t need any BWR, so just set it to zero. If you can, make a code, print it and scan it to make sure it works (there are several good barcode scanners for iOS and Android phones). If the barcode scans then your BWR is fine. If not then you may need to experiment.

If your code is going to be printed commercially on a printing press of some description then its a good idea to speak to the printing company and ask what BWR setting you should use. If they don’t know then alarm bells should ring – a reputable printer really should know that!

Scanning your code

There are several barcode scanning apps for iOS and Android on their respective app stores. You could also use a hand held scanner such as this one (click the image for more info):


…none of them will check your BWR, of course, but if you can successfully scan your printed code then your BWR was correct.

While we have your attention, why not check out our flagship barcode app on the Mac App Store?

Barcode Basics on the Mac App Store