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 Printing is a process for mass reproducing text and images using a master form or template. The earliest non-paper products involving printing include cylinder seals and objects such as the Cyrus Cylinder and the Cylinders of Nabonidus. The e ...

material in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

, and of certain other products, programs and endorsements related to their work. Among other things, the organization specifies SWOP inks used in

CMYK The CMYK color model (also known as process color, or four color) is a subtractive color model, based on the CMY color model, used in color printing, and is also used to describe the printing process itself. The abbreviation ''CMYK'' refers ...

printing, colors of SWOP

proof Proof most often refers to: * Proof (truth), argument or sufficient evidence for the truth of a proposition * Alcohol proof, a measure of an alcoholic drink's strength Proof may also refer to: Mathematics and formal logic * Formal proof, a c ...

s, other physical qualities pertaining to printing. The organization publishes its own specification and

ICC profile In color management, an ICC profile is a set of data that characterizes a color input or output device, or a color space, according to standards promulgated by the International Color Consortium (ICC). Profiles describe the color attributes of a ...

and runs a certification program. SWOP is a

non-profit A nonprofit organization (NPO) or non-profit organisation, also known as a non-business entity, not-for-profit organization, or nonprofit institution, is a legal entity organized and operated for a collective, public or social benefit, in co ...

volunteer organisation, and concerns itself only with the

. 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.

History

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, the

ANSI The American National Standards Institute (ANSI ) is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organi ...

Committee for Graphic Arts Technical Standards A committee or commission is a body of one or more persons subordinate to a deliberative assembly. A committee is not itself considered to be a form of assembly. Usually, the assembly sends matters into a committee as a way to explore them more ...

. 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. 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. 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 TVI for "K" is slightly different due to G7 calibration.

Scope

The SWOP specification covers many areas related to

print production Printing is a process for mass reproducing text and images using a master form or template. The earliest non-paper products involving printing include cylinder seals and objects such as the Cyrus Cylinder and the Cylinders of Nabonidus. The ...

, complementing, extending and limiting those in other industry standards. The specification includes (but is not limited to) the following. * A specification for the colors of the

cyan Cyan () is the color between green and blue on the visible spectrum of light. It is evoked by light with a predominant wavelength between 490 and 520 nm, between the wavelengths of green and blue. In the subtractive color system, or CMYK col ...

magenta Magenta () is a color that is variously defined as pinkish- purplish- red, reddish-purplish-pink or mauvish-crimson. On color wheels of the RGB (additive) and CMY (subtractive) color models, it is located exactly midway between red and blu ...

, 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 ISO is the most common abbreviation for the International Organization for Standardization. ISO or Iso may also refer to: Business and finance * Iso (supermarket), a chain of Danish supermarkets incorporated into the SuperBest chain in 2007 * Iso ...

-1:2006. * A specification for the colors of

proofs Proof most often refers to: * Proof (truth), argument or sufficient evidence for the truth of a proposition * Alcohol proof, a measure of an alcoholic drink's strength Proof may also refer to: Mathematics and formal logic * Formal proof, a co ...

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 Dot gain, or tonal value increase, is a phenomenon in offset lithography and some other forms of printing which causes printed material to look darker than intended. It is caused by halftone dots growing in area between the original printing film ...

(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

halftone Halftone is the reprographic technique that simulates continuous-tone imagery through the use of dots, varying either in size or in spacing, thus generating a gradient-like effect.Campbell, Alastair. The Designer's Lexicon. ©2000 Chronicle, ...

s and

color separation Color printing or colour printing is the reproduction of an image or text in color (as opposed to simpler black and white or monochrome printing). Any natural scene or color photograph can be optically and physiologically dissected into three ...

* Design constraints, such as the minimum size of type which is to printed reversed or knocked out of a background, to keep

legibility Legibility is the ease with which a reader can decode symbols. In addition to written language, it can also refer to behaviour or architecture, for example. From the perspective of communication research, it can be described as a measure of the p ...

. * 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. *

s for

color management In digital imaging systems, color management (or colour management) is the controlled conversion between the color representations of various devices, such as image scanners, digital cameras, monitors, TV screens, film printers, computer printer ...

, 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 Adobe ( ; ) is a building material made from earth and organic materials. is Spanish for '' mudbrick''. In some English-speaking regions of Spanish heritage, such as the Southwestern United States, the term is used to refer to any kind of ...

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
{{DEFAULTSORT:Specifications For Web Offset Publications Color space Printing