Making a loyalty card is mostly a set of small decisions that are easy to get wrong once and then live with for two years, because you printed a thousand of them.
What goes on the card
Four things, and most badly designed cards are missing one of them.
Who you are. Your name, and your address if you have one location. Customers put these in wallets and forget where they came from. A card with no address is a card that gets thrown away during a clear out.
The offer, in one line. "Buy 9 coffees, get the 10th free." Not "collect stamps for rewards". The specific version is understood without being read twice.
The stamp boxes. Numbered, so a customer can see how far along they are without counting. Big enough for whatever you are stamping with, which in practice means at least 12 millimetres square.
The rules. Small text, but present. Whether stamps expire, whether it works at other branches, one stamp per visit or per item. Every rule you leave off is an argument at the counter later.
Design decisions that matter
Size. Business card, 85 by 55 millimetres, fits in a wallet card slot and is cheapest to print. Postcard size gives you room but does not fit a wallet, so it lives loose in a bag and is lost within a fortnight. If ten boxes will not fit on one side, use the back.
Stock weight. At least 350gsm. Anything thinner goes soft in a pocket and looks tired by the fourth stamp, which makes the whole program feel cheap.
Finish. Matt or uncoated. Gloss laminate looks better on day one and will not take a rubber stamp or a pen, which is a problem if you ever need to write on it.
Colour. One or two colours print cheaper than full colour and often look more considered. What matters more is contrast: the stamp boxes need to stay visible once there is ink on them.
Numbered boxes. Number them. An unnumbered row of ten circles forces a customer to count, and counting is friction.
What to leave off
Fine print you do not intend to enforce. If you write "management reserves the right to withdraw this offer at any time", nobody reads it, and if you ever act on it the customer is angry anyway.
Terms in a font under 6pt. Unreadable terms are the same as no terms, with added bad faith.
A QR code that goes to your homepage. If the code does not do something specific, it just makes the card busier.
Printing
Get a proof before the full run. A stamp box that looked fine on screen at 200 percent zoom can be too small for your actual stamp, and you will not discover that until five hundred cards are in a box.
Order a smaller first run than feels sensible. Two hundred, not two thousand. You will change something after a month of real use, and cheap reprints beat a cupboard full of cards with the old offer on them.
Buy the stamp at the same time and test it on the printed proof. Self inking stamps are faster at a busy counter than a stamp and pad, and the ink dries quicker, which matters when a card goes straight back into a wallet.
Where printed cards fall down
Two problems, and they are structural rather than fixable.
Customers lose them. A meaningful share of every print run ends up in a coat pocket, a washing machine, or a bin during a tidy. Each lost card is a customer who quietly stops collecting, and you have no way of knowing how many there were or who they were.
You learn nothing. You cannot see how many people are collecting, who your best customers are, how many cards ever complete, or which of your regulars stopped coming in March. Nor can you contact anyone, because you never captured a way to.
There is a third that people do not like discussing. A rubber stamp resembling yours costs a few pounds online.
Making a digital loyalty card instead
The digital version answers the same four questions the printed card does. Who you are, what the offer is, where the customer stands, and what the rules are. The difference is what happens after it is issued.
The customer scans a QR code and joins in the browser. Nothing to download. The card sits on their phone and can be saved to Apple Wallet or Google Wallet so it appears on the lock screen near your shop.
You get the part paper cannot give you: a list of who is collecting, how often they come, and a way to contact them.
You still need a printed thing, but it is a poster or a counter card with a QR code on it rather than a card per customer, so you print it once. Setting up the QR code and poster covers the practical side.
If you already run printed cards and want to switch without annoying anyone holding a half filled one, the paper to digital checklist covers honouring existing stamps.
A reasonable starting point
Nine or ten stamps. Business card size, 350gsm, matt, numbered boxes, one line offer, address on the back, expiry set at a year of inactivity if you set one at all.
Print two hundred. Use them for two months. Then decide whether the drawer of half finished cards behind your till is telling you something.