QR codes that join paper to digital

A printed card is finished the moment it leaves the press. A code on it is not. Put a QR code on the card and everything that moves between now and the day - the running order, the map, the dress code, the reply form - lives on a page you can still edit while the envelopes are in the post. Be plain about one thing first: the code on a printed card is the same on every card, and it opens your invitation without knowing who is holding it.

Print a short run, and let the code carry the rest

This is a division of labour, not a compromise. Paper carries the part that should not change: your names, the date, the place. The code carries the part that always does.

So print for the people who need paper, and count them honestly. Grandparents. The godmother who keeps a mantelpiece for cards and would notice if yours never arrived. The great-uncle whose phone has buttons instead of a camera, who could not scan the square if he wanted to. Your parents, who want one for the drawer, and one for yourselves. Written down, that list usually comes to fifteen or twenty cards rather than a hundred and fifty - a working guess from how such lists tend to look, not a number anybody has counted for you. Everyone else receives the same invitation as a link, so the printing bill falls with the number of cards. The pricing page shows how the digital half is charged.

Two cases make this the wrong plan. If nobody on your list expects paper, a short run for its own sake is a job you invented. And if you are printing for the people who find a phone camera awkward, the card has to stand alone: date, time, venue and a telephone number in full, with the code as an extra. A card whose only real content is a square is worse than no card at all.

One card, one code, and what it cannot know

Your invitation has a QR code in the dashboard, and it opens the invitation’s own public address - the same link anybody can be given. You download it as a PNG or an SVG. Send your printer the SVG if they will take it: it scales to any size without going soft.

Because every card carries that one code, the invitation cannot greet the person holding it by name, or attach their reply to the row you made on your guest list. Personalised links do exist, but they are per guest: a printed run cannot carry them unless every card is printed individually with its own code, which stationers price as variable data work.

So here is what happens when somebody scans a card. They see the invitation. If you have left replies from the public link switched on, they get a reply form as well - and since the card told the invitation nothing about who picked it up, the form has to ask. It wants a name and a mobile number, typed in by hand. What comes back sits on your dashboard as pending: it moves no total and takes no seat until you approve it. That is the right behaviour for an object that gets photographed on somebody’s kitchen table and forwarded round a family group. If you would rather every reply came from a guest you named yourself, switch public replies off.

Where the code goes on the card

Low, small and last. The code is not part of the design and should not be the first thing the eye lands on. A few placements work, and a few fail:

• The lower third of the main card, under the date and the venue. The safe default.
• The details card, if your suite has one. The map and the timings already live there.
• Never across a fold or in the gutter of a folded card. A crease through a code is a code that will not read.
• Not under a wax seal, a ribbon or a vellum wrap. Anything on top has to come off first.
• Well inside the trim edge. Cards are guillotined with a tolerance, and a code that loses its white margin to the blade fails on the copies cut tight.

Size, quiet zone and contrast

Size decides more than anything else. Start at about two centimetres square, roughly three quarters of an inch, for a code on a card held in the hand, and nothing goes wrong by making it bigger. Print shops carry a companion figure, the ten to one: the code wants to be about a tenth of the distance it will be read from. A card in the hand is close; a sign propped on a welcome table is not. Both are trade habits passed around, not measurements taken on your stock.

The plain margin around a code is part of the code, not padding you may trim. Leave clear space on all four sides, about the width of four of the code’s own small squares. The file you download already has that margin built in, so the mistake to avoid is cropping it off.

Contrast comes last. Dark on light, always. Foil, metallic ink and a deep letterpress bite into textured stock all catch the light rather than absorbing it, so if your suite is being foiled, print the code in flat ink. Do not reverse it out white on a dark stock; sit it in a light panel instead. The code we generate is black on white at the highest error correction setting, which is what lets it carry a small heart in the middle and still read.

What to write beside it

“Scan me” is decoration, not an instruction. The line beside the code has to say what the guest gets and what you want them to do. Something in this shape:

• “Scan for directions, timings and to reply by 12 September.”
• “Scan to reply, or telephone Amara on the number below and she will do it for you.”
• “Open the camera on your phone and hold it over this square.”

Print the reply deadline in words as well as behind the code, so the guest who never scans still knows the date. And always give a name and a number beside the square. The people you printed for are the ones most likely to need it.

Before the file goes to the printer

Proof the code the way a guest will meet it, not on your screen. Print the real card on the real stock, put it under ordinary indoor light, and scan it with the most battered handset you can borrow rather than the newest one on the table. If it hesitates, make the code bigger before you change anything else.

Related: RSVP QR code for printed cards