This International Standard specifies viewing conditions for images on both reflective and transmissive media, such as prints (both photographic and photomechanical) and transparencies, as well as images displayed in isolation on colour monitors. This International Standard applies in particular to: — critical comparison between transparencies, reflection photographic or photomechanical prints and/or other objects or images; — appraisal of the tone reproduction and colourfulness of prints and transparencies at illumination levels similar to those for practical use, including routine inspection; — critical appraisal of transparencies that are viewed by projection, for comparison with prints, objects or other reproductions; and — appraisal of images on colour monitors that are not viewed in comparison to any form of hardcopy. This International Standard is not applicable to unprinted papers.