A screen plate is a photographic plate used in early additive colour photography, where separate colour filters were applied to capture or reproduce images. These plates contained a fine grid or screen that helped record different colour components, which were later combined to produce full-colour photographs.
Screen plates were an important step in the development of colour photography, enabling photographers to experiment with capturing and reproducing realistic colours before the widespread availability of modern colour films. They played a key role in scientific, artistic, and experimental photographic work in the late 19th and early 20th centuries.