dotsperinch

Dotsperinch, more commonly known as dots per inch (DPI), is a measure of spatial resolution that describes how many individual dots fit within one inch along a line. The term is used in different contexts to indicate the density of output dots on a physical medium or the sampling density of digital content. In practice, dotsperinch is closely tied to the concept of resolution, but the exact meaning can vary with the device and the workflow.

In printing, a dot is a physical mark of ink or toner laid down on paper or another substrate. Higher DPI can enable finer detail and smoother tonal transitions, but print quality also depends on ink formulation, substrate quality, and the halftoning process used to reproduce continuous tones. In this context, DPI is a device-dependent specification provided by printers and print engines.

In displays, the term DPI is often used interchangeably with pixels per inch (PPI). Strictly, DPI refers to physical dots in print, while PPI describes the digital image density on a screen. A display’s perceived sharpness depends on pixel resolution and viewing distance, and DPI/PPI alone does not determine image quality.

Common ranges include 300–1200 DPI for printers and roughly 90–300 PPI for displays, with higher values offering more potential detail but diminishing returns at typical viewing distances. When preparing images for print, it is usual to target a specific DPI (for example, 300) and translate that to an appropriate pixel count for the desired print size.