Image Resolution & DPI
Why 300 DPI is the magic number
What is DPI?
DPI stands for Dots Per Inch — it measures how many tiny ink dots fit in one inch of your printed piece. More dots = more detail = sharper print.
Think of it like a mosaic: a mosaic made of huge tiles looks rough up close, but one made of tiny tiles looks smooth and detailed. DPI is your tile size.
The 300 DPI standard
300 DPI is the industry standard for high-quality printing. At this resolution, individual dots are invisible to the naked eye — your photos look crisp, text is razor-sharp, and gradients are smooth.
150 DPI is acceptable for large-format prints (posters, banners) viewed from a distance. But on business cards or brochures held at arm's length, 150 DPI looks noticeably soft.
72–96 DPI is what most web images use. These look great on screens but will appear pixelated and blurry when printed. Never use images downloaded from websites or social media for print.
How to check your DPI
On Mac: Right-click the image → Get Info → look under "More Info" for dimensions and DPI.
On Windows: Right-click → Properties → Details tab → look for "Horizontal resolution."
In Photoshop/Illustrator: Image → Image Size — check resolution is set to 300 pixels/inch.
In printa: Our automatic preflight scanner checks every image in your PDF and tells you the exact DPI. If any image is below 300 DPI, you'll see a warning with the exact resolution found.
Cannot increase DPI after the fact
A common mistake: opening a 72 DPI image in Photoshop and changing the resolution to 300 DPI. This does NOT add detail — it just makes the file bigger. The image still has the same number of pixels. You need source images that were captured or created at high resolution from the start.