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
Color management channels are RGB (mainly for display (monitors) but also for some desktop printing) and CMYK (for commercial printing). An additional "alpha" channel may specify a transparency mask value. Some image software (such as Photoshop) perform automatic color separation to maintain color information in CMYK mode using a specified ICC profile such as US Web Coated (SWOP) v2. , most web browsers ignored color profiles. Notable exceptions were Safari, starting with version 2.0, and Firefox starting with version 3. Although disabled by default in Firefox 3.0, ICC v2 and ICC v4 color management could be enable by using an add-on or