Image Resolution for Print

Why does the same photo look perfect on your phone but blurry on the printed flyer? Why are 72 dpi sometimes plenty, while in other cases even 300 dpi falls short? And most importantly — how can you be sure that the file you send us will give a good result?

In this guide we have collected everything you need to know as a client, with no unnecessary theory — just practical examples and rules that will save you reprints and unpleasant surprises.

PPI and DPI — the Two Most Confusing Letters in Prepress

The two abbreviations are often used interchangeably, but they mean different things:

→ PPI (pixels per inch) — the pixel density of your raster file (JPG, TIFF, PSD)
→ DPI (dots per inch) — the density of dots the printing device can place on paper

When we say "send a photo at 300 dpi," we technically mean 300 ppi — the resolution of the file itself. The imaging device works at much higher resolution (typically 2400–2540 dpi on a CTP), but that is our problem, not yours.

Remember: when you talk about the file you supply — the right term is PPI.

Where the "Magic" 300 ppi Number Comes From

Standard offset printing uses a screen ruling of 150–175 lpi (lines per inch). In prepress there is a simple rule:

Image resolution = screen ruling × 2

So:

→ 150 lpi → you need 300 ppi
→ 175 lpi → you need 350 ppi
→ 200 lpi (fine art reproductions) → you need 400 ppi

That is why 300 ppi is treated as the universal minimum for quality offset printing. Above 350–400 ppi there is usually no benefit — the eye no longer resolves the difference, and file size grows exponentially.

Doubling the resolution quadruples the file size with no visible improvement in quality.

This is a common mistake — clients send images at 600 or 1200 ppi "just in case." The result is a heavy file, slower processing, and zero quality gain.

Effective Resolution Is the Real Resolution

This is where clients are most often misled. What matters is not the resolution of the original file, but what happens after you place the image into the layout.

Example:
You have a 1000 × 1000 px photo at 300 ppi. Its native print size is 8.5 × 8.5 cm. Perfect.

But in InDesign you stretch it to 17 × 17 cm. Now:

→ The native (Actual) resolution stays at 300 ppi
→ The Effective resolution drops to 150 ppi — half the minimum

The result: a blurry photo on the printed product.

Checking in InDesign

Window → Links → select the image → Link Info:

→ Actual PPI — the native resolution of the file
→ Effective PPI — the resolution at the current scale (must be ≥ 300)

If Effective PPI drops below 250, the photo will look poor. Below 200 — disastrous.

How Large Can I Print This?

Simple answer: divide the pixels by 300.

Beyond these sizes, quality drops. It is a physical limit — detail that is not in the file cannot be "invented."

The "Just Upscale It in Photoshop" Trap

Photoshop has the Image Size feature with a Resample option. Technically you can take a 1000 × 1000 px photo and "upscale" it to 3000 × 3000. Don't do it.

Photoshop cannot create detail that isn't there. It just interpolates — new pixels averaged from neighbours. You get a soft, blurry image that often looks worse in print than the original smaller version.

Cases where upscaling works acceptably:

→ AI-based tools (Photoshop Super Resolution, Topaz Gigapixel AI, Magnific) — significantly better than standard resampling, but no magic
→ Minor upscaling up to 110–120 % — usually still acceptable to the eye

Where You Should NOT Source Images for Print

→ Websites and social networks — images there are optimised for the screen (72–96 ppi) and usually under 1500 px wide. Good for a business card at most.

→ Viber, Messenger, WhatsApp — these compress images aggressively. Even if you send a 24 MP photo, it often arrives reduced to 1–2 MP.

→ Screenshots — resolution equals the screen's (typically 1920 × 1080 px), not the original object's.

→ Stock sites in "Small" size — always choose the largest available version. The price difference is usually minimal; the quality difference — dramatic.

→ Google Images — apart from the legal problems, most images there are at web resolution.

Always ask for the original file from the photographer, designer, or source — not a downloaded version from a web gallery.

When the Rules Bend: Large Format

For billboards, banners, and façade vinyls, viewing distance changes everything. What is seen from 30 metres does not need the same detail as a business card held in the hand.

Approximate practical rule of thumb:

So don't be surprised if for a 6 × 3 m billboard we tell you that a photo from a regular camera is more than enough.

Special Case: Barcodes, QR Codes, Hairlines

For these elements, the best solution is a vector file (from Adobe Illustrator or a dedicated generator). A vector image scales perfectly at any resolution, and lines remain mathematically precise.

If the element must be raster, use a resolution that is a multiple of the imaging device's output resolution (1200 ppi for a standard CTP) to avoid line-weight distortion. For barcodes this is not a question of how it looks — it is about whether the cashier's scanner can read them at all.

Resolution by Print Type

Quick Check Before You Send the File

• Resolution at least 300 ppi at the final printed size
• Colour mode CMYK, RGB only with a profile
• File format TIFF, PDF or JPG at maximum quality
• Vector elements (logos, barcodes) — in AI, EPS or PDF
• Fonts embedded or converted to outlines
• At least 3 mm bleed on every edge
• Important elements (text, logo) — at least 3 mm inside the trim line
• Don't grab images from websites, Facebook, Instagram
• Don't upscale small photos in Photoshop "just in case"
• Don't send PowerPoint or Word files as the print original
• Don't rely on the file's "300 dpi" property — what matters is the effective resolution in the layout
• Don't send photos via Viber, WhatsApp or Messenger

Got Doubts About a Specific File?

Just send it to us before production. We will check it in minutes and tell you whether it will give a good result at the final size. Better to fix it now than to reprint a finished run.