What to put your code on

Mugs

Why it works:

The best starting product, and not by accident. It sits in someone's hand every morning at exactly the moment they're not doing anything else. That's the moment you want.

Where the code goes:

On the flattest area, opposite the handle. Keep it 2 to 2.5cm, well clear of the curve at the edges.

Watch out for:

Glossy glaze throws glare under a kitchen light, and matte scans more reliably. And check the print wraps flat, because a code bending round a curve is a code that doesn't read.

How to get them made:

Print-on-demand handles this well: Printful, Printify, Gelato and most local printers all do ceramic transfer. Order one before you order fifty.

Best for:

Poems, daily photographs, a track a day, morning prompts.

Cards and postcards

Why it works:

Cheapest thing on this list to produce and the easiest surface for a code. If you want to test whether people scan at all, test here.

Where the code goes:

Front, bottom corner, with three words next to it. Not the back, because people don't turn cards over looking for things.

Watch out for:

High-gloss finishes. Matte or uncoated is better.

How to get them made:

Any local printer, or online in runs of fifty upwards for very little.

Best for:

Gifts, wedding place cards, greetings, thank-yous with something behind them.

Books and zines

Why it works:

Someone finishes your book and disappears. A code inside the back cover keeps you in their day for another forty mornings, and they're still there when the next one lands.

Where the code goes:

Inside the back cover, or on a sticker if the book is already printed. A bookmark tucked in works just as well and costs nothing to change.

Watch out for:

Tight binding: don't put the code near the gutter where the page curves into the spine.

How to get them made:

If you're printing new: straight into the layout. If the run already exists: stickers.

Best for:

Deleted scenes, character notes, chapter-opening lines, a poem a day from the same collection.

Prints and posters

Why it works:

Art on a wall is looked at once and then becomes furniture. A code turns it back into something that changes.

Where the code goes:

Bottom edge, near the signature, or on the mount. Size it for the viewing distance. A poster read from two metres wants a code around 20cm, which is bigger than feels natural.

Watch out for:

Putting the code over the artwork. Give it its own space in the margin; it's a doorway, not part of the picture.

Best for:

Studies and sketches from the same series, the working process, alternative versions.

Tote bags and t-shirts

Why it works:

It walks around. Other people scan it, which is the only product on this list that markets itself in public.

Where the code goes:

Chest or bag panel, 4 to 5cm minimum. Fabric needs more room than paper.

Watch out for:

Ink spread on textile, and heavy weaves. Stick to smooth cotton and go bigger than you'd think. Codes on stretchy fabric distort, so avoid them.

How to get them made:

Print-on-demand, DTG rather than vinyl for fine detail.

Best for:

Musicians, merch tables, anything where you want strangers scanning.

Stickers and labels

Why it works:

The most forgiving surface there is, and the cheapest way to add a code to something that already exists. If any other product on this list is giving you trouble, sticker it instead.

Where the code goes:

Anywhere flat. That's the point.

Watch out for:

Almost nothing. Just avoid clear stickers on busy backgrounds.

How to get them made:

Online sticker printers, cheap in bulk, fast turnaround.

Best for:

Retrofitting stock you've already printed, packaging, jars, anything you didn't plan for.

Packaging

Why it works:

Someone has just paid you money and is opening a box. That's the highest-attention moment you will ever get with a customer.

Where the code goes:

Inside the lid or on the insert card, not the outside. Make it part of the unboxing.

Watch out for:

Folds, seams and shrink wrap. A code across a crease won't read. Keep it on a single flat panel.

Best for:

Crowdfunder rewards, product ranges, anything where the buyer is already excited.

Keepsakes and gifts

Why it works:

Jars, boxes, frames, ornaments, engraved things. Nobody throws these away, which means your code stays in a house for decades.

Where the code goes:

On the base, inside the lid, on a small plate. Engraving works, so send the SVG and test one first.

Watch out for:

Contrast on engraved metal. Some finishes leave too little difference between the mark and the surface.

Best for:

Memorials, baby's first year, weddings, anything meant to be kept.

Notebooks and stationery

Why it works:

It's already open in front of someone who's about to think. A prompt a day belongs here more than anywhere.

Where the code goes:

Inside cover or back cover. Sticker if the notebooks already exist.

Best for:

Schools, workshops, courses, daily prompts, hobby teaching.

Not sure which to start with?

Start with whichever you can make one of, cheaply, this week.

If you sell already, put a code on your bestseller. Same product, same margins, and you'll see the difference in the reviews before you see it anywhere else.

If you're starting from nothing, go with cards or stickers. Fifty euros, a week's wait, and you find out whether people scan before you commit to anything.

If it's a gift or a keepsake, go with a mug or a box. The daily habit is the whole point, and both sit somewhere people return to.

You don't need a new loop for every product

The same code can go on a mug, a card and a print, with the same loop behind all of them. Your licence decides how many products it covers: one, three, ten, or as many as you like.

Handy if you're building a range around one body of work.