Physical development is a photographic process in which silver particles are suspended in a developer solution and are chemically attracted to areas of the emulsion that have been exposed to light. This allows the image to gradually form as metallic silver builds up on the exposed regions.
This method was historically important in early photography and is valued for producing high-quality, stable images with rich tonal range. Physical development offers precise control over density and contrast, making it useful in fine art photography, scientific imaging, and specialized darkroom techniques where image permanence and detail are critical.