QR Codes – some practical tips

June 6, 2012

in Technology

We are asked on a regular basis about what is the best size or smallest size a QR code can be printed at and still work as a scannable code.  Here are some tips and pointers on how to make your QR code work on any printable medium.

Why use a QR code?

A QR (Quick Response) code is a 2-dimensional barcode made up of little black dots (data modules).  By printing a QR code on your marketing or POS material you are allowing the reader to scan the code on their smartphone and download a whole range of information.  Users must have the correct scanning software or App on their smartphone but apart from that anyone can scan a QR code. 

As an example, using a promotion Xcaliba worked on last year for a beer brand that wanted to promote at summer festivals, we printed t-shirts to be worn by promotion staff walking around the venues.  Festival-goers could scan the code on the t-shirt with their smartphone and download a special offer allowing them to enter a competition and claim free samples from the trade-stand.  This allowed the brewer to collect huge amounts of data for their target customer base and drive people to their stand at each of the festivals.

There are no charges for using QR codes, they never expire, there are no limits on the number of times a code can be scanned, they are license-free and they have no commercial restrictions

 

How much and what type of information can be stored in a QR code?

The types of information that can be embedded within a QR code are – Website URL, YouTube video, Google Maps location, Social Media links, iTunes links, plain text, SMS message, email address, email message, contact details (VCARD), event details (VCALENDAR) and Wi-Fi login (currently Android only).

You can store over 4000 characters in a QR code but the more characters held within the code, the smaller the modules and therefore the further away you need to be to scan the code effectively.   A Version 1 QR code can hold 25 characters and has a module grid of 21 x 21 whereas a Version 40 QR code can in theory hold up to 4296 alphanumeric characters and has a module grid of 177 x177.  For QR codes that need to be read by mobile phones it is best to keep the QR code to Version 4 or lower, otherwise the modules are smaller than the resolution capacity of the scanning software.

 

What size do I need to print my QR code at?

There is no clear cut answer for this but it is possible to use some guidelines.  Firstly, thinking about how a QR code is scanned, the initial consideration is how far from the code will the user be?  The QR code really needs to be at least 2cms square within the viewport of the scanning device.  If the code is being scanned from a distance, on a back-of-bar poster for example, then the size of the QR code needs to be large enough to be seen clearly in the camera viewport.  if you print a QR code onto a business card then it can obviously be scanned from a much closer distance and can therefore be printed at a smaller size.

The other consideration is the amount of data being stored within the QR code.  the greater the amount of data, the smaller the blocks that make up the code and therefore the larger the QR code may need to be to allow for the resolution of the scanning device to read the modules effectively.  It is recommended that a QR code has no more than 50 rows and columns to stay within the accepted resoultion of most smartphone cameras.

Assuming that the QR code has the correct amount of data to keep within the resolution capacity then we would suggest the minimum printed size of a QR code is 20 x 20mm.   It is also important to leave a clear unprinted border or ‘quiet zone’ of 4 modules width around your QR code .

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