Baby hand and footprints: when, what from, how to keep

Up to roughly the fifth or sixth month the grasp reflex is at work: whatever touches the palm, the hand closes around. It isn't defiance and you won't beat it by prising the fingers apart — the hand opens when you hold it by the wrist and run your thumb along the back from wrist to knuckles. It then opens by itself for exactly the second you need. A sleeping baby is the best collaborator, even if that isn't what it looks like.

A foot is easier, which is why it works more often with babies. Touching the sole does trigger the toes to curl too, but the surface is bigger and it prints even with the toes tucked in: press the heel down first, then roll the foot onto the surface, and never push on the pads of the toes.

The worst window runs from about six months to eighteen months. The child moves, reaches for the material and tastes whatever isn't being printed at that moment. Either put it off for a few months, or count on two adults — one holding and talking, one printing. After the third birthday it becomes a joint project, and it is worth it: next to a newborn print, the new hand becomes a measure, not just another picture on the wall.

The difference between materials isn't in how the print looks on the first evening, but in what an ordinary home does to it: swings in humidity, dust and the grease from hands. The table runs from the most durable flat prints down to the relief ones.

Salt dough is the cheapest and least durable option, and that is exactly what makes it treacherous for a keepsake: it looks finished and falls apart at the point when nobody can repeat it — the hand has grown in the meantime.

The culprit is salt. It pulls water out of damp air, so dough that was biscuit-hard in December gives way in summer, bulges and grows mould underneath. Varnish doesn't fix it, it only seals the problem in: moisture gets in through the untreated back and then has no way out from under the varnish. If salt dough it is, then a finger thick at most, dried long and low — hours in the oven with the door ajar rather than half an hour on full — and stored somewhere dry. Not the attic, not the cellar, not the bathroom.

The second thing is safety. Salt at this concentration is not food. A dog that takes an ornament off a low branch of the tree swallows a dose of salt it would never meet in an ordinary day, and a toddler will put the dough in its mouth too — it's colourful, it smells of baking and it hangs low. A dried ornament therefore belongs out of reach and off the tree, filtered the same way as toys for the youngest children.

A plaster cast is the only way to keep the real shape of the hand, fingernails and all. But it comes with a rule that internet tutorials often lose: a child's hand must never go into setting plaster. As it sets, plaster reacts with water and gives off heat; in a narrow cup clamped around the fingers it gets hotter than you expect, and at the same time it hardens around the hand. A burn and a trapped hand are both real possibilities here.

The right way is two-stage, and that's also why kits are sold the way they are. First you mix alginate — the seaweed-based moulding material you know from the dentist. It sets within a few minutes in lukewarm water and stays flexible, so you can pull the hand out with the fingers intact. Only then does plaster get poured into that mould. The mould survives one cast, then dries out and warps, so a second attempt means fresh alginate — which is why you should buy enough for two batches from the start.

The finished cast then dries for several more days and is soft: it scratches with a fingernail and partly dissolves in water, so it never gets washed. Brush the dust off with a soft brush. Greasy hands will grey it permanently and no amount of cleaning brings that back.

The most common cause of a ruined print isn't clumsiness, it's rushing the last three seconds. This order of steps solves that.

Years later what stings isn't how the print looks, but that nobody wrote down whose it is and when it was made. Ten years on you won't tell two siblings' hands apart. Write in pencil, on the back, straight away — and put down more than the date: write the circumstance, because that can't be worked out from a photo. The same rule goes for a dedication in a book: a specific detail outlives a pretty sentence.

Storage decides durability more than the material does. Even well-fired ceramic won't survive a bathroom — it just takes longer to happen.

A print is by its nature a one-off. If it crumbles, there is nothing to make a second one from — the hand that made it no longer exists. That is exactly why it pays to have, alongside the physical keepsake, one that can be produced again: a photograph, a full-size scan, a print from that scan.

The same reasoning is behind a personalized children's book. It is created from a single uploaded photo, so the hero looks like that particular child, and the name is set into the story in the correct grammatical forms, because the text is written directly in the given language. It is a one-off purchase with no subscription — and if something happens to the paper, the source remains. A print shows how small the child was; a book shows what they were like back then. What is worth keeping from the first year and what wears out before anyone notices is covered in the article on keepsake gifts for a first birthday; how such a book comes about is described in a personalized book step by step.