cyan, magenta, yellow and black ("key") inks used in CMYK printing. Inks conforming to the specification can be called SWOP inks. The specifications make reference to, but are not identical to, the ISO standard ISO 2846-1:2006. A specification for the colors of proofs produced by various technologies, so they are accurate representation of the SWOP inks eventually used to print. (See SWOP Certification Program below). Proofs made from systems that meet these specifications may be called SWOP Proofs. Specifications for expected dot gain (caused by ink dots enlarging over absorbent papers), also known as tone value increase (TVI). G7-based versions use an alternative definition (see CGATS TR015). Requirements for producing halftones and color separation Design constraints, such as the minimum size of type which is to printed reversed or knocked out of a background, to keep legibility. Production constraints, such as a limit of 300% on the total mixture of inks (taking a mixture of 100% each of cyan, magenta, yellow and black as being 400%). SWOP also endorse, produce or specify some other things. ICC profiles for color management, based on the standard called TR001, an ANSI technical report whose full title is “CGATS TR001-1995 Graphic Technology-Color Characterization Data for Type 1 Printing.” A number of profiles using TR001 are made with SWOP in the title, such as the profile USWebCoated (SWOP), which is widely available because it is included with many Adobe applications. TR001 profiles are not universal, because they were generated and tested with specific inks, papers, and printing technologies. The SWOP booklet gives the specifications mentioned above, often in reference to other industry specifications (ISO and other). A SWOP Certification Program for proofing (not press) printing systems. This is used by manufacturers, rather than purchasers, of systems. References External links SWOP Frequently Asked Questions SWOP Website GRACol website, contains SWOP 2013. CGATS Technical Reports Color space Printing