DPI stands for dots per inch and measures how densely a printer can place ink dots on paper. A 300 DPI print places 300 ink dots in every inch of paper width and height, producing crisp text and continuous-tone photographs. 600 DPI is high-quality fine-art printing. 72-150 DPI is rough draft quality. Below 72 DPI, individual dots become visible to the naked eye at normal viewing distance.
For architectural rendering, DPI matters when the render is destined for print. A 300 DPI standard requires that your render be at least width-inches × 300 pixels wide. A render that will print as a 12-inch portfolio page needs to be 3600 pixels wide at minimum to avoid visible pixelation. Below that, the print will show the pixel grid of the source render, which looks unprofessional at close viewing distances.
DPI doesn't apply directly to screens — screens display pixels at their native resolution, not at a print-derived DPI. When designers say a screen is '300 DPI' they typically mean it has roughly 300 pixels per inch of physical screen surface, which is similar enough in concept but not the same measurement. For digital-only deliverables, focus on pixel dimensions and aspect ratio; DPI matters only when print is the output.
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