What DPI do you need for a sharp poster print?

For a sharp poster, aim for images at 150 to 300 DPI at the final print size. A screen only displays around 72 DPI, so a picture that looks crisp on your monitor can print soft or pixelated — the extra detail simply is not there.

What DPI actually means

DPI (dots per inch) is how much detail is packed into the print. More dots per inch means a finer, sharper image — up to a point. For close-up print like flyers and business cards, 300 DPI is the standard. For posters, which you view from further back, 150 DPI at full size is usually plenty.

The reason viewing distance changes the number is simple: your eye can only resolve so much detail at a given distance. A business card sits 30cm from your face, so it needs the full 300 DPI to look crisp. An A1 poster on a wall is read from a metre or more away, where 150 DPI looks every bit as sharp because your eye cannot pick out the finer dots anyway. A billboard read from across a car park can be lower still. Matching the resolution to the viewing distance saves you fighting to source impossibly large files for no visible gain.

Why bigger isn’t always sharper

Enlarging a small image does not add detail — it just spreads the existing pixels, which softens the result. The key number is the resolution at the final size, not the file’s pixel count on its own.

Here is the trap: software will happily let you scale a small photo up to poster size, and on screen it may even look acceptable. But blowing up a 1000-pixel image to a metre wide does not invent new detail — it stretches each pixel until the edges go soft and blocky. No amount of sharpening or “enhancing” recovers detail that was never captured. Always judge an image at 100% zoom at its intended print size; if it looks soft there, it will look soft on the wall.

Vector art stays sharp at any size

Logos and graphics supplied as vector files (AI, EPS or PDF) can be scaled to any size without losing sharpness — ideal for large posters and banners.

Vector art is built from mathematical paths rather than a fixed grid of pixels, so it redraws itself perfectly clean at any size — a logo that is razor-sharp on a business card is just as sharp blown up across a banner. Where you can, supply logos, type and line graphics as vectors, and reserve high-resolution photos for the photographic parts of the design. That combination gives you crisp text and edges alongside rich imagery.

Preparing files the right way

A few habits make posters print cleanly. Build the file at the final size (or a clean fraction of it) rather than designing small and scaling up at the end. Set the colour mode to CMYK, since that is how the piece is printed — bright RGB screen colours can shift when converted. Add a few millimetres of bleed if artwork or colour runs to the edge, so trimming leaves no white slivers. Keep important text and logos clear of the very edges. Exporting a print-ready PDF with fonts embedded is the safest way to hand a poster over, and it avoids the fonts reflowing on our end.

Common mistakes to avoid

The frequent ones: pulling an image straight off a website (web images are usually 72 DPI and small, so they rarely hold up in print), scaling a phone snapshot far past its real size, and saving a heavily compressed JPEG that carries visible blocky artefacts into the print. If the only version of an image you have is small, tell us — we can usually advise the largest size it will print cleanly before it starts to soften.

Frequently asked questions

What resolution do I need for an A1 or A2 poster?

Aim for 150 DPI at the finished A1 or A2 size for a crisp result viewed from normal distance. If the poster will be studied up close, push towards 300 DPI. Vector elements like logos and text stay sharp regardless.

Can you fix a low-resolution image for me?

We can sometimes improve a borderline image, but we cannot create detail that was never in the file. The honest answer is usually to source a larger original or reshoot — send us what you have and we will tell you what it can do.

Is 72 DPI ever enough?

For very large-format work viewed from a distance — a big banner or a hoarding — a lower resolution can be fine because the viewing distance is so great. For anything read up close, it is not.

Should I supply RGB or CMYK files?

CMYK is preferred because that is how the poster prints. If you only have RGB, send it anyway — just be aware very bright screen colours can shift slightly on conversion, and we will flag anything that will not reproduce well.

Not sure your image is big enough? Send it to us and we will tell you the largest size it will print cleanly before it starts to soften. See our poster printing options or get a quote.