What is Resolution and DPI?
Why does a photograph that looks great on screen appear muddy or pixelated in print? The truth about DPI.
DPI and Resolution: The Pixel Trap
One of the most frustrating moments for the NowToPrint team is when a customer asks: "My logo looked fantastic on screen — why does it look blocky and jagged on my business card?"
The answer lies in the difference in Dot/Pixel Density (DPI) between your computer screen and the print machine.
What Does DPI (Dots Per Inch) Mean?
DPI expresses how many ink droplets (dots) fit within one inch (2.54 cm).
- Your digital screens (phones, monitors) need only 72 dots (72 dpi) to display an image clearly.
- Physical paper and print machines require at least 300 dots (300 dpi) for a crystal-sharp result.
Phone Camera vs Logos
A 10-megapixel photo taken on your phone is reasonably high quality. However, the moment you send it via WhatsApp, the app compresses it by approximately 70% and reduces it to 72 DPI. Never prepare print files from WhatsApp images.
Images Found via Google
An image found and saved from a search engine may appear enormous on screen, but that size is only digital. When printed on paper, it reduces by 300% or degrades enough for the pixels (squares) to become clearly visible.
What Happens to Files Below 300 DPI?
If you upload a PDF containing raster images (JPEG, PNG, etc.) below 300 DPI to NowToPrint servers, one of two things occurs:
- Preflight Rejection (Quality Protection): The system detects severely low-resolution images (below 150 DPI) and issues a
Pixel Warning(Quality Error) to prevent wasted spend. - AI Upscaling Activates: If a borderline image (e.g. 200 DPI) is submitted, our AI Engine attempts to repair the missing pixels using Deep Learning technology and "upscale" the image toward 300 DPI. This often works, but it is not magic — it cannot replace the quality of an original high-resolution source.
The Golden Rule: Choose Vector Format!
If you want to eliminate pixel problems entirely, work with vector graphics in Adobe Illustrator, CorelDRAW, or SVG format.
Composed of JPEG, PNG, or Photoshop files. Because it is built from pixels (squares), it degrades and loses sharpness when enlarged. Photographs are necessarily in this format.
Text and drawings (logos). Vector graphics are mathematical formulae. A logo in EPS or PDF format will not degrade in the slightest even if printed at building scale (infinite DPI).
Always process text in your designs using vector-based software (Illustrator, InDesign) when saving to PDF — never in Photoshop. Otherwise, thin text elements will suffer from pixelation.
The Forced Resize Trap
Taking a 72 DPI JPEG into Photoshop and forcing it to "300 DPI" via Image Size does not improve its quality. It only increases the blurriness. To achieve genuine high DPI, you must use the original raw (RAW or Hi-Res) source file.
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