Specifications for Web Offset Publications, invariably abbreviated to SWOP, is an organization and the name of a set of specifications that it produces, with the aim of improving the consistency and quality of professionally printed material in the United States, and of certain other products, programs and endorsements related to their work. Among other things, the organization specifies SWOP inks used in CMYK printing, colors of SWOP proofs, other physical qualities pertaining to printing. The organization publishes its own specification and ICC profile and runs a certification program.
SWOP is a non-profit volunteer organisation, and concerns itself only with the United 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 GRACoL originally by Graphics Communication Association, which defines a similar set of specifications for sheetfed printing. By 2005, both specifications are merged into a think tank called IDEAlliance with their own working groups. By 2006, both are unified under the framework of CGATS 21.[1]