Specifications for Web Offset Publications, invariably abbreviated toSWOP, is an organization and the name of a set of specifications that it produces, with the aim of improving the consistency and quality of professionallyprinted material in theUnited States, and of certain other products, programs and endorsements related to their work. Among other things, the organization specifiesSWOP inks used inCMYK printing, colors ofSWOPproofs, other physical qualities pertaining to printing. The organization publishes its own specification andICC profile and runs a certification program.
SWOP is anon-profit volunteer organisation, and concerns itself only with theUnited States. In some other areas, similar efforts have been made by other organisations, taking account of national variations in printing techniques, expectations, and requirements.
Similar to SWOP is General Requirements for Applications in Commercial Offset Lithography (GRACoL) originally by Graphics Communication Association, which defines a similar set of specifications forsheetfed printing. By 2005, both specifications are merged into a think tank calledIDEAlliance with their own working groups. By 2006, both are unified under the framework of CGATS 21.[1]
Early work of specifying U.S. print color started in 1975 and resulted in a set of best practices, the precursor to SWOP. By the late 1980s, digitization of printing lead the SWOP committee to seek cooperation with CGATS, theANSICommittee for Graphic Arts Technical Standards. The result was CGATS TR001, an ANSI technical report that specifies the colorimetric measurements of standard SWOP ink and media. In 2005, SWOP was merged into IDEAlliance.[1]
GRACoL was founded in 1996 with the goal of specifying sheetfed printing in a similar way to SWOP. Annual specifications were published from 1997-2002. In 2006, SWOP and GRACol (coated CPRC6, uncoated CPRC3) was redefined in the G7 calibration method, which is also used in ISO/PAS 15339 or CGATS 21 defining the Characterized Reference Print Conditions (CPRCs). The standard defines SWOP as CPRC5, coated GRACol as CPRC6, and uncoated GRACol as CPRC3.[1]
GRACoL-SWOP 2006 uses the ISO 12647-2:2004 paper. The 2013 revision uses a slightly bluer paper as the old paper is considered legacy by the authors. GRACoL/CPRC6 aligns mostly with ISO 12647-2 PC1, although the Tonal Value Increase (TVI) for "K" is slightly different due to G7 calibration.[1]
The SWOP specification covers many areas related toprint production, complementing, extending and limiting those in other industry standards. The specification includes (but is not limited to) the following.
SWOP also endorse, produce or specify some other things.