DPI
Also known as: Resolution, Pixels Per Inch, PPI
Dots Per Inch — the resolution of a raster image. 300 DPI at print size is the rule.
DPI (dots per inch) measures how densely a raster image's pixels pack into a printed inch. 72 DPI is fine for a screen; 300 DPI is the standard for print. Below 200 DPI, prints start to look soft, and below 150 DPI you see visible pixelation.
The trick: DPI changes when you scale the image. A 300 DPI photo printed at its native size looks crisp. The same photo printed at 200% size is effectively 150 DPI — half as sharp. Always check the DPI at the actual print dimensions, not the file dimensions.
For screen printing, 200–300 DPI is the working range. For DTG and DTF, 300 DPI is preferred. For embroidery, DPI is irrelevant — the design is digitized into stitches anyway.