An X-ray developer is a specialized chemical solution used in darkroom radiography to convert latent images into visible ones. During the image processing sequence, X-ray films are first immersed in the developer solution. The developer acts as a reducing agent, donating electrons to reduce exposed silver halide (silver bromide) crystals into black metallic silver in the film’s emulsion layer. This metallic silver forms the radiolucent (black) areas on the radiograph that represent exposed regions.