In photography, a negative is an image, usually on a strip or sheet of transparent plastic film, in which the lightest areas of the photographed subject appear darkest and the darkest areas appear lightest). Negatives are loaded into a camera and exposed to light, creating a reverse image where light areas look dark and dark areas look light. Color negative films are more complex and have multiple layers, appearing primarily red when viewed, but all colors are visible when printed. Negatives are normally used to make positive prints on photographic paper by projecting the negative onto the paper with a photographic enlarger or making a contact print). The paper is darkened in proportion to its exposure to light, so a second reversal results which restores light and dark to their normal order). Negatives were once commonly made on a thin sheet of glass rather than a plastic film, and some of the earliest negatives were made on paper). Positives on film or glass are known as transparencies or diapositives, and if mounted in small frames designed for use in a slide projector or magnifying viewer, they are commonly called slides).