July 13, 2026
Every year, brands waste printing budgets and delay campaign launches because they didn’t account for one thing: the US and most of the rest of the world use different paper size standards. When you’re running a domestic wheatpaste campaign in New York or Los Angeles, your files are probably set up in US sizes — 11×17 (Tabloid), 18×24, 24×36. Ship those files to a print vendor in London or Berlin, and you’ll get either confused vendors, reprints that don’t match your layout, or posters that simply look wrong on the wall.
This isn’t a minor technical footnote. International poster sizes — the ISO A-series system — have different proportions than US standard sizes. The math matters. If you just scale a US-sized file to fit an ISO sheet, your margins shift, your typography gets compressed or stretched, and your layout can look completely off. We’ve seen it happen on expensive campaigns that had solid creative and fell apart in production because nobody addressed the file conversion question until it was too late.
This guide covers exactly what you need to know: the differences between US and ISO paper systems, how to convert correctly, what the file preparation process looks like for international markets, and what to watch for when working with print vendors who operate outside the US standard. It’s written from firsthand experience coordinating print production for international wheatpaste campaigns across the UK, Europe, and Latin America over more than a decade.
The US uses a paper size system inherited from pre-metric traditions. Common sizes are defined in inches and don’t follow a consistent ratio relationship. ISO A-series, used in the UK, Europe, Australia, Latin America, and most of the rest of the world, is based on a ratio of 1:√2 (approximately 1:1.414). This ratio is special because it means you can fold an A-series sheet in half and get the next size down with the same proportions. It’s an elegant system — and it’s fundamentally incompatible with US sizes.
| US Size | Dimensions (inches) | Closest ISO Size | ISO Dimensions (mm) | Ratio Difference |
|---|---|---|---|---|
| Tabloid | 11 x 17 | A3 | 297 x 420 | Minor — manageable with recompose |
| 18×24 | 18 x 24 | A2 | 420 x 594 | Moderate — layout adjustment needed |
| 24×36 | 24 x 36 | A1 | 594 x 841 | Significant — recompose recommended |
| 27×40 | 27 x 40 | A0 | 841 x 1189 | Moderate — usually requires recompose |
The temptation when converting a US-format artwork file for international production is to just scale it. Scale the 24×36 up or down to fit A1. It’s a 5-second fix in any layout application. The problem is that scaling doesn’t account for the aspect ratio difference — it just stretches or compresses the image to force it into new dimensions.
For some poster types, scaling works fine. A full-bleed photography poster with no text elements close to the edges can often be scaled to ISO dimensions with minimal visible impact. The image just gets slightly cropped or slightly letterboxed, depending on which direction you scale.
For most commercial wheatpaste designs, scaling creates real problems:
Typography that’s balanced for a 24×36 composition — headline at the top, body text in the middle, call-to-action at the bottom with specific margins — will look cramped or stretched when scaled to A1 proportions. The horizontal-to-vertical relationship of your text blocks changes. What was well-spaced looks packed. What was centered looks slightly off. The effect is subtle enough that it won’t look catastrophically wrong, but it will look like something is slightly off — which is worse than looking clearly wrong because it’s harder to identify and fix.
Brand marks with specific clear space requirements are particularly vulnerable to scaling. If your logo requires a certain amount of clear space relative to its size, scaling the entire composition proportionally will just scale the clear space too — maintaining the relative proportion but potentially not meeting the absolute minimum requirements at the new size.
Designs with elements close to the trim edge — phone numbers, URLs, or key visual elements that sit near the border — risk getting cut off when scaled and reprinted on a slightly different sheet size. What was 0.5 inches from the edge on a US 24×36 might end up 0.3 inches from the edge on A1, which at large format can fall outside the print bleed zone.
The right approach to artwork conversion for international wheatpaste printing depends on your source file format. Here’s the process for the most common scenarios.
Vector files are the easiest to work with for size conversion because they’re resolution-independent. The process:
The bleed specification difference is actually worth noting. US print production typically uses 0.125-inch (approximately 3.175mm) bleed. ISO markets use 3mm bleed as standard. For most practical purposes these are close enough that a file prepared for US production will work fine in ISO markets, but if you’re setting up a fresh file for international production, use 3mm.
InDesign handles multi-size document workflows reasonably well. You can create an alternate layout at ISO dimensions within the same document. InDesign will attempt to reflow content, but for poster layouts this usually needs manual adjustment. Use the alternate layout as a starting point, then recompose manually rather than trusting the reflow to be correct.
This is where it gets harder. Raster files created at US dimensions have a specific pixel count. When you resize them to ISO proportions, you’re either cropping or adding canvas. For a full-bleed photo poster this is usually manageable. For a poster with embedded text elements (text that’s been rasterized rather than live type), any size change will either distort the text or require redrawing from scratch.
The strong recommendation here: never rasterize text in your source files for wheatpaste campaigns. Keep text as live type in layered source files. This makes size conversion infinitely easier and also makes language localization possible without rebuilding the file.
Paper size conversion is only half the technical challenge. Resolution is the other half, and it catches designers who work primarily in digital just as often.
Wheatpaste posters are viewed close-up on the street — someone walking past at arm’s length to a few feet away. This is different from billboard viewing distance. The resolution requirements are actually higher for street posters than for large-format billboard vinyl, because the viewing distance is shorter.
| Size | Minimum Pixel Dimensions (150 DPI) | Preferred Pixel Dimensions (300 DPI) | Notes |
|---|---|---|---|
| A2 (420x594mm) | 2480 x 3508 px | 4961 x 7016 px | Fine for most applications |
| A1 (594x841mm) | 3508 x 4966 px | 7016 x 9933 px | 300 DPI recommended for fine type |
| A0 (841x1189mm) | 4966 x 7016 px | 9933 x 14043 px | 150 DPI acceptable for bold graphics |
| 2A0 (1189x1682mm) | 7016 x 9933 px | 14043 x 19866 px | 150 DPI minimum; multi-sheet builds acceptable |
Many agencies prepare campaign assets at screen resolution — 72 or 96 DPI at some nominal size — because they’re primarily producing for digital channels. Those files are completely unusable for wheatpaste at street scale. Always check the actual pixel dimensions of any file you plan to send to a print vendor.
This one trips up even experienced production teams. Print files need to be in CMYK color mode, not RGB. Digital files are RGB. The conversion from RGB to CMYK changes how colors render, and the conversion needs to happen at the design stage — not at the print vendor’s end.
US print vendors who specialize in street marketing materials are used to receiving files from agencies and converting them if needed. International vendors vary more widely. Some UK and European print shops will convert RGB files without flagging it; others will print from RGB and you’ll get unexpected color shifts. The safest practice is always to deliver CMYK files with an embedded color profile (typically ISO Coated v2 for European printers or Fogra 39).
Colors that look great on a monitor in your New York office can shift significantly in print, particularly highly saturated colors like electric blue, neon yellow, and vibrant red. If color accuracy is important to your campaign — and for brand work, it always is — request a print proof before full production runs, regardless of market.
This is something few brands think about before they send files overseas, but it matters: different paper stocks take wheatpaste differently. Uncoated papers adhere better and hold up better in wet weather. Coated papers print sharper but can peel more easily in rain or humidity.
Our American Guerrilla Marketing field operators have firsthand experience with which paper stocks work in which markets and conditions. London gets rain — frequently. A paper choice that works in the relatively dry spring climate of New York might fail in a wet London autumn. Mexico City in rainy season is a completely different environment from Mexico City in February.
This is one of the reasons we recommend using local print vendors rather than central print-and-ship for markets with highly variable weather conditions. Local operators know what stock holds up in their climate. That knowledge saves campaigns.
If your international wheatpaste campaign includes language localization — different copy for UK English versus US English, Spanish for Mexico City, German for Berlin — you need a clean file management system before production begins. Nothing creates more expensive mistakes than unclear version control on multi-language campaigns.
The naming convention that works in practice:
[CampaignName]_[Language]_[Size]_[Version].[format]
For example: BrandX_EN-UK_A1_v3.pdf or BrandX_ES-MX_A0_v2.pdf
Each market’s print package should include only the files relevant to that market, clearly labeled, with a one-page print spec document that spells out the size, bleed, color mode, and any other production details. Don’t make print vendors figure out which file is which from a folder full of ambiguously named files.
Finding reliable print vendors in international markets is something our nationwide network and international operator relationships handle, but if you’re managing production yourself, a few things to know:
The UK has a well-developed large-format print industry. Vendors in London and Manchester who specialize in outdoor poster production are experienced with A-series formats and wheatpaste-weight papers. Look for vendors with experience in outdoor and street-level applications — not just trade show graphics or banner printing.
Germany, France, and the Netherlands have strong print industries. German vendors in particular are known for exacting quality standards and will flag any file issues before printing rather than proceeding and sending an invoice. If you send a German printer a substandard file, expect a detailed email explaining exactly what’s wrong. That’s actually a feature, not a bug.
Mexico City has a dense print industry, particularly in the colonias near the Centro Histórico. Quality varies more widely than in Europe, and pre-production print proofs are more important here than in markets with more standardized quality control. Our operators in Mexico City work with vetted vendors they’ve used across many campaigns — firsthand relationships matter more in this market than in others.
Before any artwork file leaves your hands for international production, run through this:
This sounds like a lot of steps, but once you’ve done it once it becomes second nature. The brands that get it right on their first international guerrilla marketing campaign are the ones who had someone walk them through the production requirements before they started. The ones who find out at the last minute are the ones calling us at 11pm asking if there’s anything that can be done about files that just arrived at a Berlin print shop in the wrong format.
There usually is something we can do. But it’s always better not to be in that situation.
American Guerrilla Marketing coordinates wheatpaste campaigns across the US and international markets from a single New York contact.
Scaling works for some files but not all. If your layout relies on a specific aspect ratio — a letterhead-style composition, text anchored to the bottom third, or a centered product shot — recomposing to ISO proportions is almost always better than scaling. Simple full-bleed image posters scale fine. Complex typographic layouts rarely do.
UK wheatpaste operators typically work in A1 (594 x 841mm) and A0 (841 x 1189mm). Doubled A0, sometimes called 2A0, is common for large-format street placements. All of these are ISO A-series dimensions, not US sizes.
Print at 150 DPI at final output size minimum. 300 DPI is better for fine typography. At A0 size (841 x 1189mm), 150 DPI means a pixel dimension of roughly 4966 x 7016 pixels. Most designers working in digital-first environments have files that are too small for this without visible pixelation at large format.
You need at minimum one US-standard file and one ISO-standard file. If you’re also doing language localization, you’ll need separate files per language version. For a three-country campaign in the UK, Mexico, and Germany, you’d typically have three size variants and three language variants — potentially nine files total depending on size requirements per market.
Yes. AGM works with our production partners to handle file conversion, size adaptation, and print-ready file preparation for each market. We flag any layout issues that would affect the conversion before anything goes to press.
American Guerrilla Marketing coordinates wheatpaste campaigns across the US and international markets from a single New York contact.
Millie Phillips
Campaign Architect — American Guerrilla Marketing
Email: [email protected]
Office: (646) 776-2770
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American Guerrilla Marketing — Los Angeles
Street-level campaigns in Los Angeles and nationwide. Wheatpasting, LED trucks, street teams, and more.
(646) 776-2770
July 14, 2026
July 14, 2026
July 14, 2026
July 14, 2026
July 14, 2026
