Test QR code before printing: the table card that opens your menu

Why test QR code before printing

A table card for a cafe costs little on its own. A thousand of them do not. If the code on the card fails, every one goes in the bin, and the menu it was meant to open stays out of reach until the reprint arrives.

The screen preview cannot tell you much. A code on a bright monitor is sharp, large and lit from behind. The printed card will be smaller, on paper or board, under a cafe lamp, sometimes behind a plastic stand. That is the version you need to test.

So test QR code before printing with a plan you can repeat for every job: three phones, two distances and one proof print. It takes about twenty minutes. The plan below uses a menu table card, the folded tent card that stands on each table, as the printed object. The code on it opens the cafe's menu page.

Start with the proof print

Ask the printer for one proof on the same board, the same finish and the same size as the final run. A home inkjet print on plain paper is not a proof. Ink spreads differently on coated board, and a gloss or matt laminate changes how light bounces off the code.

Check three things on the proof before you pick up a phone.

First, the size. On a table card, make the code at least 30 mm wide, and 40 mm is safer. Measure it with a ruler on the proof, not in the design file. Printers sometimes scale a page to fit, and a 40 mm code can come back at 34 mm.

Second, the quiet zone. This is the plain margin around the code. It should be at least four of the code's small squares wide on every side. On a 40 mm code that is about 4 mm. If a border, a logo or a fold line runs into that margin, phones struggle.

Third, the contrast. The code should be dark on a light ground. Black or deep navy on white or cream works. Light grey on white does not. A white code on a dark card can work on some phones and fail on others, so avoid it on a long run. If you want brand colours, preview the colours and shapes in the QR colour and shape demo first, then keep the dark parts truly dark.

Three phones, not one

Your own phone is the worst one to test with. It is probably recent, its camera is good, and you know exactly how to hold it. Your customers bring every kind of phone.

The first phone is a recent one with a good camera. It shows the code can work at all.

The second is an older budget phone, three or four years old. Its camera focuses slower and handles low light badly. This is the phone that finds most problems.

The third is a phone with a scratched lens or a cheap screen protector over the camera, or simply a friend's phone you have never used. It stands in for the customer who is not careful.

On each phone, use the built-in camera app, not a scanning app. Most people never install a scanner. Point, wait, and count the seconds until the link appears. If it takes longer than about two seconds on any phone, treat that as a fail.

Two distances, and the light in the room

Test at two distances that match how people hold the card.

The near distance is 0.25 m. That is a phone held over a card on the table, by someone sitting down.

The far distance is 0.6 m. That is someone reaching across a table for two, or leaning back in their chair. A rough rule says a code scans well up to about ten times its own width. So a 40 mm code is comfortable to 0.4 m. At 0.6 m you are past the rule, and that is the point. If all three phones still read it there, the card has room to spare.

Do the far test in the room where the cards will stand, at the time of day the cafe is busiest. Evening light from a warm lamp is harder than daylight. If the card goes in a clear acrylic stand, test it inside the stand. Glare from a gloss laminate or acrylic can wash out half the code at one angle. Tilt the phone a little and see if it recovers. If it only works at one exact angle, change the finish to matt.

Check what the code opens

A code that scans is half the test. The other half is the page it opens.

Tap the link on each phone. The menu should load in a few seconds on mobile data, not only on the cafe's wifi. Turn the wifi off for this step. Check that prices, item names and opening hours are current. Check that the page reads well on the small screen of the budget phone, with no tiny text and no sideways scrolling.

With a dynamic code, the printed pattern opens a short link, and the short link points to the menu. That means you can change the menu page later without reprinting the cards. It also means you should test the re-pointing once before the print run. Point the code to a test page and scan it. Point it back to the menu and scan again. Then you know the change works when you need it.

Write down the result before you sign off

Keep a short record for the job: the code size measured on the proof, the board and finish, the three phones used, both distances, the light, and the time each scan took. If any phone failed at any distance, write down why and what you changed.

Only then tell the printer to run the thousand. The record also helps on the next job. A poster or a pack will need its own sizes and distances, but the method is the same.

If you also hand out the cards at a market stall or an event, tell us where you sell and we will suggest a size and finish for each place.

You can order a code that opens your menu and can be re-pointed later from the restaurant menu QR page.