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 ("kallfü") and green ("karü", also meaning "raw" or "immature"). The word "payne" was formerly used to refer to a sky blue, and also refers to the bluish color of stones (Zúñiga, 2006). Blue–green distinction in language Many languages do not distinguish between what in English are described as "blue" and "green" and instead use a cover term spanning both. To describe this English lexical gap, linguists use the portmanteau word "grue", from "green" and "blue", which the philosopher Nelson Goodman coined in his 1955 "Fact, Fiction, and Forecast" to illustrate the "new riddle of induction". The exact definition of "blue"