Image Resolution: Why 300 DPI Matters

Image resolution affects how sharp photographs, illustrations, and other raster graphics appear when printed.

StationeryHQ's general file setup requirements specify a minimum resolution of 300 DPI for bitmap and raster images.

DPI means dots per inch. In artwork preparation, designers often use the term interchangeably with PPI, or pixels per inch, when discussing image resolution.

What happens when an image has low resolution?

A low-resolution image may look acceptable when viewed at a small size on a screen but appear blurry or pixelated when enlarged for printing.

This is especially noticeable in:

Photographs
Fine illustrations
Small decorative details
Text embedded in raster images
Detailed artwork used in invitations and stationery

How do you calculate the required pixel dimensions?

For a raster image intended to print at 300 PPI:

Pixels = final image size in inches × 300.

For example:

Print size	Approximate image dimensions at 300 PPI
3.5 x 5 inches	1050 x 1500 pixels
4 x 6 inches	1200 x 1800 pixels
5 x 7 inches	1500 x 2100 pixels
8 x 10 inches	2400 x 3000 pixels
8.5 x 11 inches	2550 x 3300 pixels

These are examples for the finished image dimensions, not a replacement for adding bleed to the overall print file.

Can you increase resolution in Photoshop?

You can change an image's resolution setting, but simply changing the DPI number does not create additional original image detail.

For the best results, start with a sufficiently large original image or illustration.