Glossary → DPI
DPI.
dots per inch
The number of ink dots a printhead lays down per inch of image, and the resolution figure on every spec sheet. Reaching a higher DPI costs either more passes or a higher firing frequency, so it trades directly against line speed. A 1200 dpi head is denser than a 600 dpi one, which is not the same thing as better or faster. The word does a second job that has nothing to do with the head, and it is the one a customer means: the resolution of the artwork at the size it will be printed. The POD platforms answer that question in three incompatible ways. Printful asks for print files "At least 150 DPI" as a floor but recommends 300 for DTFlex, and for fine lines or text on All-Over Synthetic, Printify recommends 300 DPI and drops to 120-150 DPI on its largest products, and Redbubble tells sellers that DPI and PPI do not affect the uploaded image and publishes pixel dimensions instead. Redbubble is the one that is technically right, because DPI in a raster file is metadata a platform can overwrite while it scales the art to its own print area. Quote a customer a DPI number without saying at what printed size, and you have told them nothing you can hold them to.
Where this matters: DTG printing › Resolution at print size · DTF › Resolution at print size · Sublimation › Resolution at print size · Wall decor › Poster and canvas print DPI: resolution at print size · Screen printing › Resolution at print size · Embroidery › Resolution at print size · UV printing › Resolution at print size · HTV and vinyl › Resolution at print size · Resolution and DPI › What “resolution” means before any number · Resolution and DPI › Printer output resolution is not a file rule · KDP spine width, bleed and cover size › Resolution at print size · Stickers › Resolution at print size · Mug and tumbler template sizes, DPI and seam › Resolution at print size · All-over print › Resolution at print size