Poster type is judged on a screen at somewhere between 25 and 50 per cent zoom, and printed at 100 per cent on paper with a texture. Almost every typographic failure in print-on-demand comes from that gap, and almost all of it is predictable before you spend anything on a proof.
None of this is about taste. These are physical constraints with numbers attached.
Screen size is not print size
Judging an A3 layout in a window on a 27-inch monitor means looking at it at roughly 40 per cent. Every decision about the smallest text on the poster is being made at less than half the size it will exist at, which is exactly backwards — you are most confident about the element you can see least well.
Two habits fix it. Zoom the document so that one image inch measures one physical inch against a ruler held to the screen, and look at the type at that scale. Then, before publishing, print one A4 crop of the busiest corner at 100 per cent on any printer you own. Not the whole poster scaled to A4 — a crop at true size. That sheet costs a few pence and catches more problems than an hour of zooming.
The smallest sheet sets the type floor
A digital download listing usually offers a stack of sizes from one file. The buyer picks A5 or A3 and prints accordingly, and the type scales with the sheet.
So a detail line set at 9pt on an A3 layout arrives as 4.5pt when the same file goes to A5, because A5 is half the linear dimension of A3. At 4.5pt, letterspaced, in a light weight, on textured paper, it is a grey smear with a shape.
The rule that follows is simple and almost nobody applies it: set the smallest element for the smallest sheet you sell. Decide the floor — call it 7pt on cotton rag — then work out what that has to be on your master. If the master is A2 and the smallest offer is A5, that is a factor of four, so the detail line is 28pt on the master. If that looks absurdly large in the layout, your size range is too wide and should be split into two files rather than stretched across one.
The same logic applies to hairline rules, and they fail earlier than type does. A 0.25pt rule under the place name becomes 0.06pt at quarter size, which will either vanish or print as an intermittent dotted line depending on the paper.
Ink spread closes counters
On coated stock, ink sits on the surface. On the uncoated matte and cotton rag papers that fine-art printing uses, it wicks into the fibres and every stroke lands fractionally wider than specified.
Thin strokes gain proportionally more than thick ones. That does three things: high-contrast faces lose their hairlines, small counters — the enclosed spaces in a, e, g, 8 — fill in, and tight letterspacing closes into a solid block.
Reversed type is the worst case. White letters on a dark ground get eaten from every side at once, so a light weight that reads perfectly as black-on-white can lose its thin strokes entirely when flipped. If your poster has a dark band with type in it, step the weight up one notch from what looks right on screen and set it a touch larger.
This is also the argument against very light weights in a range sold as a digital download. You do not know the buyer's paper. Regular and medium survive anything; hairline weights depend on a printing process you have no control over.
Tracking moves in the opposite direction to size
Capitals are drawn with sidebearings sized for mixing with lowercase. Set them large and alone and they look loose, so a display place name in caps generally wants slightly negative tracking — enough to close the gaps without letters touching.
At small sizes the reverse holds. Ink spread and reduced size both work to close the letters up, so a country name or a coordinate line in caps at 8pt needs generous positive tracking, often a great deal of it, before it reads as deliberate rather than cramped.
One consequence catches everyone. Tracking applies space after the last letter as well as between letters, so a centred line of widely tracked caps sits visibly left of centre — by half the tracking value, which at heavy letterspacing is a millimetre or two on the sheet. Delete the trailing space or nudge the block right by half. Once you know to look, you can spot it on other people's posters from across a room.
The other rule, which is old and still correct: do not letterspace lowercase. Caps and small caps yes, lowercase never.
The trim edge is not where you think
Two things happen at the edge of the sheet and they compound.
The printer trims, with a tolerance of a millimetre or two on a good lab. Then the buyer frames it, and almost every frame overlaps the sheet by three to six millimetres to hold it in the rebate.
So the effective safe zone is set by the frame, not the trimmer. Type sitting 8mm from the trim can end up 3mm from a visible edge, off centre relative to the visible area, or partly under the moulding. On A3 and larger, keep type at least 15mm inside the trim and you have room for both. On A5, keep the proportion rather than the millimetre count.
This is a second, quieter argument for the deep bottom band on a mounted square layout: the type lives in the middle of a generous area of paper, nowhere near anything that might get cut or covered.
Hierarchy needs steps, not nudges
A travel poster typically carries three levels — the place, the country or region, and a detail line such as coordinates or a date. What makes it read as a hierarchy is the ratio between them, not the absolute sizes.
The place name wants to be three to four times the height of the qualifier. A difference of ten or fifteen per cent does not read as hierarchy; it reads as a mistake, because the eye interprets small unexplained differences as error rather than intent. If two levels are close in size, separate them by weight, case or colour instead — or accept that you have two levels rather than three.
Watch the interaction with the size floor here. If the detail line is pinned at your minimum for the smallest sheet, and the place name is four times that, the place name's size is now decided for you. Hierarchy and legibility are the same constraint approached from opposite ends, and on small sheets they will meet. That is usually the moment to drop the third level entirely on the small sizes rather than shrink everything.
Figures, primes and the degree symbol
Coordinate lines are where amateur typesetting shows most, because they are made almost entirely of characters people substitute without noticing.
Use the degree sign ° (U+00B0), not the masculine ordinal º, which is narrower and sits at a different height. Use prime ′ and double prime ″ for minutes and seconds, not the apostrophe and the double quote, and certainly not curly quotes — autocorrect will insert those for you unless you stop it.
Set figures as lining rather than old-style. Old-style figures have descenders and varying heights, which is right inside running text and wrong in a line of caps, where they look like a typo. If the face offers tabular figures, use them, so that coordinate lines across a range of forty posters all occupy the same width and the block sits identically on every sheet.
Faces that hold at small sizes
What survives shrinking: open apertures, large counters, moderate stroke contrast, a decent x-height. Most grotesques and neo-grotesques, and serif faces designed for body text.
What fails: high-contrast display faces whose hairlines thin to nothing, and geometric sans faces with small x-heights, which are perfect at display size and lose ground fast as they shrink.
The named trade-off worth stating plainly: Futura and its relatives are the correct historical face for a mid-century travel poster and have a small x-height. That is fine for the place name, which is set in caps at display size, and it means the qualifier and detail lines need setting a size or two larger than a grotesque would to read the same. Use the period face for the big word and, if the small lines are fighting you, set them in something that holds — nobody notices two faces used with discipline, and everybody notices an illegible coordinate line.
Before you publish
Outline or embed the fonts in any PDF you deliver, or the buyer's printer will substitute something and your careful hierarchy becomes Arial. Embedding permissions are a licensing question separate from whether the file works, and worth checking once per face rather than once per project.
Then print the crop at 100 per cent. Every constraint on this page becomes obvious on a single A4 sheet, and none of them are obvious on a monitor.
Frequently asked questions
What is the smallest text size that prints legibly on a poster?
Around 6pt is the practical floor on smooth paper and closer to 7 or 8pt on textured cotton rag, where the ink spreads into the fibres and closes up the counters. The number matters less than where you measure it, though: the floor applies to the smallest sheet you sell, not the size you designed at. A 9pt detail line on an A3 layout becomes 4.5pt if the buyer prints the same file at A5, which is below what most home printers resolve cleanly. Set the smallest element for the smallest sheet and let it grow from there.
Why does my poster text look thinner on screen than in print?
It does not — it is the reverse, and the mechanism is ink spread. A screen renders a stroke at exactly the width you specified, while ink on uncoated or textured paper wicks into the paper fibres and lands slightly wider than the plate or nozzle intended. Thin strokes gain proportionally more than thick ones, so high-contrast faces lose their hairlines and small counters fill in. Reversed type, white on a dark ground, suffers most, because the spread eats into the letter from all sides.
How far from the edge should poster text sit?
Far enough to survive both the trimmer and the frame, which means the frame usually sets the limit rather than the printer. A lab trims with a tolerance of a millimetre or two, but almost every frame overlaps the sheet edge by three to six millimetres to hold the print in its rebate. Type sitting 8mm from the trim can therefore end up 3mm from a visible edge, or partly hidden. On A3 and larger, keeping type at least 15mm inside the trim leaves room for both.
Should I letterspace capitals on a poster?
Yes for small caps and secondary lines, no for the large display word. Capitals are drawn with sidebearings meant for setting alongside lowercase, so at display size they look loose and need slightly negative tracking to close up. At small sizes the opposite is true, and a country name or a coordinate line set in caps reads better with generous positive tracking. One catch worth knowing: tracking adds space after the final letter too, so a centred line of tracked caps sits visibly left of centre until you remove that trailing space.
Which typefaces hold up best at small sizes in print?
Faces with open apertures, generous counters and moderate stroke contrast — most grotesque and neo-grotesque sans faces, and text-weight serifs designed for body copy. What fails is high-contrast display faces whose hairlines thin out and disappear, and geometric faces with small x-heights, which look correct at display size but lose legibility fast when shrunk. Futura is the standard example: it is period-correct for travel posters and needs its secondary lines set a size or two larger than a grotesque would to read equally well.