Понимание стандартов и технических характеристик печати в полиграфической отрасли

ppzhan news:

At present, the definitions of standardization building include: standards, specifications and methods. "Standards" are relatively widely applied and pass the assessment and recognition procedures of some management body (such as ISO); "specifications" are detailed descriptions of standards designed for a certain job; and "methods" are the approaches, techniques or procedures for something or for carrying out something.

In the printing industry, ISO12467 is an industry standard; GRACoL and SWOP are printing specifications, which use characteristic data sets to specify particular printing processes and printing materials; and G7, which has been advocated for several years now, is a method — a method for adjusting proofing and/or printing systems to obtain the expected gray balance and tonal curve.

Industry standard: the ISO12467 standard

ISO12467 (Graphic technology — Process control for the production of half-tone colour separations, proof and production prints) was developed on the basis of comprehensive data from printing quality committees in many countries around the world. It is a series of standards that provides a small parameter set of technical attributes and visual characteristics for various printing processes. The standard provides manufacturers and printing practitioners with guiding principles that help set equipment to a standard state. Measurement data from these printing plants can be used to create ICC color profiles and to generate proofs that match the printing colors.

The ISO12647 standard helps printing practitioners, prepress departments and print buyers exchange information.

The ISO12647 standard is a standard built on standards including those for ink, paper, measurement and visual observation conditions.

The ISO12647 standard includes 7 parts, each addressing a different printing process and defining the small values of the parameters for that process

ISO12647-1: Process control for the production of half-tone colour separations, proofs and production prints: parameters and measurement conditions

ISO12647-2: Offset lithography

ISO12647-3: Coldset offset lithography on newsprint

ISO12647-4: Publication gravure printing

ISO12647-5: Screen printing

ISO12647-6: Flexography

ISO12647-7: Proofing processes working directly from digital data

Industry specifications PSO, GRACoL, SWOP and JapanColor: to help printers achieve the ISO standards

The offset printing production standard PSO (ProcessStandardOffset) was drawn up by Fogra, the Graphic Technology Research Association in Munich, Germany, for BVDM (the German Printing and Media Industries Federation) for the German printing industry to implement. PSO is also built on the basis of the printing process standard ISO12647-2. PSO strictly follows the ISO12647-2 specification while adding some supplementary specifications, in particular for digital proofing, or in cases of conflict with solid colors, giving priority to midtone colors.

GRACoL, the General Requirements for Applications in Commercial Offset Lithography, is a color reproduction specification for sheetfed offset lithography. GRACoL7, in accordance with the ISO12647-2 printing standard, adopts the "neutral print density curve", or takes NPDC as its core content, specifying the standard conditions and methods of realization for printing.

To a certain extent, the difference between the two approaches PSO and GRACoL is very small; both of them advocate that midtone control is more important than solid color control.

The SWOP® standard is aimed at web offset printing. SWOP is the color reproduction specification for web offset printing. The SWOP specification applies to rotary offset printing using ISO-specified inks and papers. Two SWOP specifications exist: SWOP3 for printing on paper No. 3, and SWOP5 for printing on paper No. 5.

JapanColor is a specification and certification system established by the Japan Printing Machinery Association, aimed at encouraging the widespread adoption of printing standards throughout Japan's printing industry. JapanColor conforms to ISO standards and is similar to the GRACoL and PSO specifications; it provides guidelines for sheetfed offset, newspaper and web offset printing, and these guidelines have been specially revised to suit the particular needs of the Japanese printing market.

Industry method G7: the method used to achieve GRACoL and SWOP. G7, this control method running from proofing to printing, provides a relatively new approach to press and/or proofing color calibration. From print buyer to design agency to printing plant and back to print buyer, G7 entirely establishes a closed-loop, visually based control method. Using this method, we can in fact print on almost any kind of press or substrate while retaining a common and consistent visual effect. G7 applies not only to commercial printing but equally to publication and newsprint printing, as well as flexographic printing, screen and inkjet printing.

G7 is built on the foundation of data imaging, spectrophotometric technology and computer-to-plate technology. It is based on the theory that visual effect — that is, how an image appears in the human eye, from dark tones to light tones — is mainly controlled by gray tones, rather than by measuring the printed dot area. G7 is named after this gray calibration technique (G) and the seven ISO inks (7); it emphasizes the gray balance data of light tones and midtones rather than density targets, such as the solid density and dot gain of each color. G7 gives definitions of gray balance and of the neutral print density curve (NPDC), and takes these as the basis for calibration and image reproduction, thereby ensuring that files created using the G7 method have similar visual effects when printed by any printing process.

Standardization is letting printers follow simple rules recognized by industry experts and their customers. The ISO12647 unified standard is a set of simple procedural frameworks that make your printing more certain and effective and, more importantly, printing carried out using color measurement and color management [encyclopedia] technology can provide image quality and consistency, improve the quality of the products an enterprise delivers to its customers, and thereby reduce the time and resources of printing plants and their customers.

——This article is reprinted from China Packaging Network (pack.cn), original link: http://news.pack.cn/show-362179.html