Every "paper is dead" article opens with a scan-rate statistic. We are not going to do that, because we do not have one worth quoting and most of the ones circulating have no traceable source. What follows is an argument from mechanics: what each format can structurally do, what it cannot, and when the difference actually matters.

What paper is genuinely good at

Paper gets dismissed too fast, usually by people selling the alternative. Its advantages are real and none of them are nostalgia:

It has no failure mode. No battery, no signal, no camera permission, no app, no loading state. A card handed over works in a loud bar, a basement trade show, and a country where your recipient's data plan does not roam.
It is an object. It sits in a jacket pocket and reappears three weeks later. A scan that got saved into a phone is invisible until someone deliberately searches for it. Physical objects prompt; digital records wait.
The handover is a social ritual. Two hands, a pause, eye contact. Asking someone to take out their phone and point it at you is a different, slightly more demanding transaction.
It carries production value. Paper weight, edge finish and letterpress communicate something about your business instantly and non-verbally. A URL cannot do that.

What paper is structurally bad at

It is frozen at the moment of printing. New number, new title, new company — the box in your drawer becomes waste.
Corrections cost a print run. A typo means reordering, and the wrong cards are already in circulation.
It holds almost nothing. No portfolio, no menu, no case study, no calendar.
It leaves no evidence. You cannot tell whether five hundred cards produced five hundred conversations or none.

What the QR adds — and what it costs

A QR code on a card is not a replacement for the card. It is an extension of it, and it changes exactly four things:

The destination becomes editable. With a dynamic code, the card in someone's wallet points wherever you say it points today. This is the single biggest structural difference between the formats.
Capacity becomes unbounded. The card stays a card; the page behind it can hold your whole portfolio.
The handoff becomes one tap. Scan, save contact — no typing a phone number off a card into a keypad, which is where a large share of paper cards quietly die.
Something becomes measurable. A dynamic code routes through a redirect, so scans can be counted, timed and roughly located. That is available in analytics, and what those numbers mean is worth reading before you over-interpret them.

The costs are just as concrete. The scan needs a working phone, a connection and a willing person. The destination depends on a provider continuing to exist — a real risk covered in static vs dynamic QR codes. And a badly designed code that fails to scan in front of someone is worse than no code, because it makes you look like the thing did not work.

Where the QR clearly earns its place

Your details are likely to change

If there is a reasonable chance of a new title, number or employer inside the life of a print run, a dynamic code is the difference between editing a page and reordering a box. This is the strongest case and it applies to most employed people.

You hand out cards in volume

Conferences, expos, open houses, market stalls. High volume is where manual contact entry breaks down completely, and where a one-tap save is a genuine mechanical improvement rather than a novelty.

The next step is a link, not a phone call

If your actual next step is "look at my listings", "see the portfolio", "book a session", or "read the menu", then the useful thing is not a phone number at all. Paper cannot carry it and a code can. Estate agents, photographers, trainers and consultants all sit here.

You need to know whether the print run did anything

Distinct codes per event or batch let you tell which materials produced scans. That is not a conversion rate — it is scan data, and it tells you about attention, not revenue. But attention data beats no data when you are deciding whether to print again.

Where paper alone still wins

Your audience will not scan. Some rooms will not take their phone out for a stranger. Know your room, and believe it over an article.
The card is the brand. If the object itself is doing persuasive work — a designer, a restaurant, a luxury service — a functional square can undercut it. Put it on the back, small.
The environment is hostile. Bad signal, low light, hands full of drinks and plates. A scan has more ways to fail than a pocket does.
Volume is tiny. If you hand out one card a month, the whole apparatus is not earning its setup cost.

The version that beats both

Keep the paper card. Put the code on the back, labelled with what scanning gets you. The paper does the physical, social and brand work it has always done; the code carries the updatable, unbounded, measurable half. The two failure modes barely overlap — if the scan does not work, the printed details still do.

That is not a compromise. It is the only configuration where nothing is given up.

How to decide in three questions

Will anything on this card change within a year? If yes, it needs a dynamic code.
Is the thing I want people to see bigger than a card? If yes, it needs a page behind the scan.
Do I need to know whether this print run worked? If yes, it needs to be trackable.

Three noes and paper is genuinely fine — spend the money on better stock instead. One yes and the code has earned its place on the back.

The build takes about two minutes: see how to make one, decide what sits behind the scan in what goes on the back, or read how it works first. More on the blog, and the rest of the starting points are in the template library.

→ Put a QR on the back of your card