T-grain refers to a specific type of grain structure found in certain photographic films, particularly in black-and-white photography. This grain structure is characterized by its elongated shape, which allows for finer detail and smoother tonal transitions in images. T-grain films are often preferred by photographers for their ability to produce high-quality images with less visible grain. The term "T-grain" is derived from the shape of the silver halide crystals used in the film's emulsion. Unlike traditional grain, which appears more random and clumpy, T-grain crystals are more uniform and flat. This results in improved sharpness and clarity, making T-grain films popular among professionals and enthusiasts alike.