Grained

Grained is an adjective describing something that shows a grain—the small, repeated units that make up the overall texture of a material. It is used in contexts ranging from the microstructure of solids to the visible pattern of wood, and to the perceived texture in photographs and film.

Materials science: In polycrystalline substances such as metals and ceramics, the material is composed of grains—crystallites with distinct orientations—separated by grain boundaries. The grain size and distribution affect properties such as strength, hardness, and toughness. Generally, smaller grains increase yield strength (the Hall-Petch relation) but can reduce ductility; processing methods such as annealing, recrystallization, and thermo-mechanical treatment control grain size and orientation. Materials may be described as fine-grained, coarse-grained, ultrafine-grained, or nanocrystalline.

Wood and natural materials: In wood, grain refers to the direction of the wood fibers as they grew. Straight, spiral, or interlocked grain affects appearance and workability, including cutting direction, finishing, and strength. The grain also defines the pattern visible on quartersawn versus plainsawn boards and influences the location of growth rings.

Film, photography, and imaging: Grains or graininess describe the visible texture caused by the discrete units of exposure in film or digital sensors. In film photography, true film grain can be aesthetic; in digital imaging, higher ISO or sensor noise creates a grainy appearance. Techniques exist to minimize or emulate grain, such as denoising algorithms or deliberate film-grain emulation.