“Scanning...” “Hold over QR code.” “Scanning...”
My QR code reader was in a loop of error messages and had no intention of snapping out of it.
“Hold over QR code…”
The real-estate section of our Sunday paper was chock full of QR codes. Most of them didn’t include any instructions—make that none of them. Realtors in our area seem to assume everyone knows what a QR code is and how to use it. Fine with me, but the question is: DO people know how to use them?
Anyone can print a QR code, but making it readable seems to be a challenge at times. My reader had no problem picking up some of the other QR codes, so what was the problem with this specific barcode? (If I got frustrated, I can only imagine how the other recipients felt.)
Let’s look at some QR code basics. I know, “the basics”... how boring. But if folks are out there sabotaging codes at this basic level, how can we progress to the more fancy applications (cups, hats, etc.) I want to talk about in my next post.• The size.
According to several industry experts, it’s recommended to use a minimum size of 32×32 mm or 1.25×1.25˝, excluding the quiet zone, for QR codes that contain a URL. This guarantees that all camera phones on the market can properly read the barcode.
Granted, as new phones and their cameras improve in resolution, you theoretically can make the code smaller. But—and this is a big but—with a smaller code, you only allow the newest phones to scan your code. You lose the ability for any older phones (and in this technology-driven age, any phone older than two months is an antique) to read your code.
Changing the code size to 26×26 mm or roughly 1˝ square still covers 90 percent of the phones on the market. But the smaller your code, the smaller your audience will be.• The substrate.
Theoretically, you can print QR codes on anything, even Sunday papers ;-). But they work best on flat, non-textured, non-shiny surfaces.
What does this mean from a paper perspective? The more porous your sheet—especially something like newsprint—the higher the likelihood of dot gain, which in turn will muddy up the pixels and make the code harder to read.
Generally speaking, it’s best to keep the code larger on an uncoated porous sheet so that even with any dot gain, you do not lose the code’s definition.
If you didn’t have a chance yet, check out the video of the QR code on the Fizz Coaster
I shared with you last week. Definitely a porous substrate, but they kept the code nice and large, and it worked well.
An easier-to-use substrate, especially when you’re looking into QR codes of one inch and smaller, is a super smooth or coated sheet, with very good ink holdout. This gives you greater control over dot gain, and the resulting crisp printed code can be read with no problem.
• The contrast.
The higher the QR code to paper contrast, the easier it is to read. Black on white printing is ideal. The code on the Fizz coaster I just mentioned could even be read in a darker environment, like a bar...I tested it.
But that does not mean you have to forgo any color options. You can print on yellow, light blue or all manner of colored sheets, but aim for a contrast ratio of 30-35 percent. Meaning if you print on a pink paper, make sure the code is at least 35 percent darker than the sheet. The emphasis is on “at least.”
These are some very basic guidelines, but obviously not basic enough for my error-chasing real-estate code.
Upon closer inspection and measurement, the code was .75 inch in size (too small), on newsprint (high dot gain), and with very little contrast (red code on dark orange background). Really?
Remember, whatever your code size, substrate or color, make sure to test, test, test. Use an iPhone. Use a Blackberry. Use an Android operating system. Just Test.