Gum bichromate negatives of cyan, magenta, and yellow or red, green, and blue are used for a full-color image. Some photographers prefer substituting the cyan emulsion in the CMYK separations with a cyanotype layer. A simple duotone separation combining orange watercolor pigment and a cyanotype can yield surprisingly beautiful results. Low density photographic negatives of the same size as the final image are used for exposing the print. No enlarger is used, but instead, a contact printing frame or vacuum exposure frame is used with an ultraviolet light source such as a mercury vapor lamp, a common fluorescent black light, or the
Blue–green distinction in language from light blue to light grey. However, the term for a green apple, such as a Granny Smith, would be "ubhal glas". The boundary between colors varies much more than the "focal point": e.g. an island known in Breton as "Enez glas ("the blue island")" is called in French "l'Île Verte ("the green island")", in both cases referring to the greyish-green color of its bushes, even though both languages distinguish green (as in lawn grass) from blue (as in a cloudless midday sky). The Romance terms for "green" (Catalan ', French ', Italian, Portuguese, Romanian and Spanish ') are all