If you have followed my QR Code posts here and here and here on Business Darlings, I’ve explained how to use use QR codes to market products or services through social media.
A QR code, which stands for Quick Response is a two-dimensional matrix code that has embedded data, text or a URL printed with in the code itself. This code can be read by a QR reader device or by a Smartphone using a QR Reader application. Many Smartphones have QR reader apps pre- installed at no charge.
Once created, QR Codes can be printed on flyers, business cards and marketing materials which when scanned will send a user to a designated place such as a Facebook page or to a website. Codes can also be uploaded to websites as images which when scanned will direct users to coupons, Twitter accounts, sales pages or can direct a user to dial a phone number.
There are a number of code generators available but one in particular that I like to use is Social QR Code . This site offers the user an array of code-generating choices for use in social media optimized in an easy-to-use manner. I upgraded to the professional version last week which allows for multiple social media links to appear on a Smartphone as opposed to just one. I highly recommend this Social QR Code for social media usage. (A sample of this multiple social media code has been provided below labeled Version 2.)
Alex Lui of Five Ace Printing asked an interesting question on my Facebook page last week, “What size should the codes be?”
The standard size offered on most QR generating sites is sufficient but there may be instances where size will matter. A code size may need to be modified to ensure maximum scanner readability depending upon certain factors which are:
1) Amount of data contained within a code
2) The distance at which the code will be read/scanned by a smartphone
3) The environmental lighting where the code will be scanned AND the use of a dark(er) background color showing through the code (some other color than the preferred white background)
I contacted a few QR code generating site owners who unanimously indicate that a code for the web should be at least 1 inch by 1 inch.
Here’s the math
It is safe to state that a user who is sitting at a desk will be scanning about 8 or 9 inches from the display. Given that the scanning area on the phone is about 1 inch by one inch; where the user can easily adjust for distance simply by moving the QR reader back and forth until the code can be easily read by the phone, using a 1 inch by 1 inch dimension will work well. So when creating the code on SocialQRCode.com, download the code provided and square off to that dimension.
However, if you are creating a code for a larger area such as a wall or for a sign on a car, the code will need to be much larger since it will be scanned from a distance.
According to the author of QRstuff.com the ratio between size of the code and the distance at which it is to be read should be 10:1.
The author states, “For most smartphones the relationship between scan distance and minimum QR code size is approximately 10:1 so a 2.5cm (1 inch) QR code printed in a magazine will have a nominal effective scan distance of about 250mm (10 inches), and a QR code on a billboard 20 metres (65 feet) from the where a passer-by would be scanning it would probably need to be about 2 metres (6.5 feet) across. There’s a bit of latitude here depending on the sort of smartphone but 10:1 is a good rule of thumb for a well-lit black and white QR code being scanned front-on.”
However if a code is to be printed on a dark(er) background, the author suggests reducing that ratio from 10:1 to 8:1. And the same reduction in the ratio applies if the code is placed in an area which is not well-lit such as behind a retail counter or in a dark conference room.
So the formula for calculating the size of a QR code is:
Minimum QR Code Size = Scanning Distance / 10 – for black code printed on white paper in a well-lit area scanned ‘front on’.
OR
Minimum QR Code Size = Scanning Distance / 8 – for black code printed on darker colored paper and/or to be read in a low-light not to be read ‘front on’.
Data Density matters too!
Many QR generator sites create simple code containing URLs leading to a sales page or to a Facebook page. Simply created codes do not generate high density dots thus making it easier for a scanner to read. If complex information is added to a QR code, the dots become smaller to accommodate the additional data. Dots which are closer together make it more difficult for the scanner to read the code so the actual code itself must become larger.
Follow me here…QR codes density is broken down into ‘versions’.
“The density of the code is described by a version number that is based on the number of rows and columns of dots. A Version 1 QR code will have 21 rows and 21 columns of dots and the version number will then increase by 1 for every 4 extra rows and columns – a Version 2 QR code will have 25 rows and columns, a Version 3 will have 29 rows and columns, right through to a Version 25 that will have 117 rows and columns.”
If a code is generated with a lot of data, the code will need to be larger in size because if the image is too small, the scanner cannot read closely aligned code.
For example, a Version 2 code which only contains 25 rows and columns contains a website URL. Whereas larger URLs such as Google Maps would generate a “…a Version 6 or Version 7 QR code with 41 or 44 rows and columns of dots.”
Important: The dots within the code need to be 0.016 in size (0.4mm or greater) as this is the resolution in which the scanner will read the code effectively.
“QR codes containing vCard contact details have notoriously high data densities and will result in Version 10 or Version 11 QR codes with more than 60 rows and columns of dots.”
Samples of Versions 2, 6 and 10 code are depicted below; each containing increased data from one version to the next. Compare the three samples and note how the dots become more dense as the data which has been entered is larger. Version 2 contains a simple blog URL. Version 6 contains a Google Maps link. Version 10 contains Vcard text.
Version 2 - 25 rows x 25 columns
Version 10 - 57 rows x 57 columns
Using a long URL shortening service such as bit.ly will greatly reduce the data in a QR code and make it much easier for the scanner to read.
The take away – If you are using QR code for a website with simple URL information encapsulating the code, the size generated from most any QR code generating sites will work fine without any modifications. However, if you wish to get creative and use QR code on fabric or on a wall, consider the distance at which you expect the scanning to occur and the amount of data created with the code. Make size adjustments for dark colored backgrounds following. Following a 10:1 ratio will be suitable for most business purposes.
Always remember to test code over and over. Ask other people to scan your code and test it on multiple devices, if possible.
