Foreign popular printing specifications

Editor's note: I believe printers often hear SWOP. What is SWOP? If we encounter similar terms in order to receive foreign orders, what guidance can we obtain? The following provides some basic information and experience for reference:
General specifications: SNAP, GRACOL, SWOP, and DDAP
All of the above specifications or guidelines are mostly made by some associations in the industry based on their own requirements for printing. They are not in the form of Standards. Therefore, there are many situations in which they are stipulated. These are briefly described as follows:
SNAP: Specification for newspaper Advertising Production. This specification first appeared in 1984 and was revised in 2000. It is aimed at advertising, producers and newspaper printers using newspapers for printing purposes. Therefore, it basically does not apply to packaging and offset industries.
GRACOL: General Requirements for Applications in Commercial Off set Lithography, this guideline was published in 1996 to establish and improve the communication between offset printers and customers so that the language used and understanding are consistent.
DDAP: Digital Distribution of Advertising for Publications. Built on the SWOP standard to adapt to the guidelines of today's digital age, when used to digitally transmit advertisements, the sender and receiver are made more aware of the situation of both parties.
SWOP: Specification for Web Offset Publications, published in the mid-1970s, with 8 changes, is now used as the 9th revision of the 2001 amendment. The purpose of the use of SWOP is to allow a certain level of printing quality to be determined beforehand from the buyer of a print to the production of color separation to the middleman until production. Therefore, the focus of the SWOP is not on the printing itself but on the writing. From the basic spirit of the 1999 edition, this point can be clearly explained: The focus is on monitoring and pointing out what type of drafting system and its related parameters, and making the manuscript made available to the industry as a reference.
The central idea of ​​SWOP is: how to use the basic values ​​in the agreement so that each printing process can obtain a stable and predictable quality from production to printing.
Summary of SWOP 9th Edition: I believe more and more foreign customers are using this guide to communicate with you, so the guidelines are simplified as follows:
Retrieval: According to ISO 3664:2000, visually illuminate any printed matter with a 5000K (D50) light source. When each sheet is faded, five similar sheets of paper must be put on the back of the paper for the backing paper. This requirement applies to any type of paper. , including inkjet printing is also established.
Bottom paper requirements: ISO3664P1
Word line requirements: All defined as young line, hairline, etc. must be monochrome or not allowed to overprint the anti-white line can not be thicker than 0.007 inch anti-white land is better than 70% of the main color network overprinted word line can not be younger than When the 0.004-inch exposure is light, the dark part is exposed by the light color, and the exposed part must be sufficient to compensate for the dew-white problem caused by overprinting.
Negative film operation: It can create 2% point positive film on PS plate. Operation: It can create 4% CTP operation on PS plate. Requires 1% point of reconstruction based on different digital operation. The response paper is less than 5% of the adaptation area. This area depends on the operation of negative film, positive film, or CTP.
Cable: Line 133 is a guideline that requires the other cable to be clearly defined during the production process. Web corners: Each color is separated by 30°. The 45° screen angle is the main tone screen angle. It is generally used for magenta, which is 45° Magenta, 75° Black. ,90°Yellow,105°Cyan If the GCR is used in large quantities, the ink is the dominant color, then 45° is black, ie, 45°Black, 75°Magenta, 90°Yellow, 105°Cyan. Producers or print buyers should clearly indicate and agree to print the effect gray balance before printing: The gray performance on a 5,000-kilogram visually well-reproduced gray paper should indicate the required print gray tone TAC, UCR, GCR Technology 1. TAC cannot be more than 300%;
2. In the absence of shadow details, TAC can be enlarged to 325%;
3. GCR and UCR should be used as specified in the annex to SWOP.
When you receive a proof that claims to be the SWOP standard, in fact, in addition to receiving a visual proof, you can also know a lot of relevant data from the system he uses.
Each set of SWOP standard proofing system comes with the following information:
1. The Lab Color's Lab value and its error;
2. The Lab value of the paper used and its error;
3. The density of the Process Color used and its error;
4. 50% of each Process Color's network value and its error.
It is recommended that if you receive a SWOP script, look for the above information in your scripting system vendor. Do two things first:
1. The difference between the hue of the ink used for printing and the reference data, such as magenta, is the same as the color and saturation of the foreign ink.
2. Whether or not the provided draft is still in line with its own standards. If you have been writing for some time, there has been a change of color.
If there is no problem with the sample, and the ink we use is close to its standard, pay attention to:
1. The network points are value-added. Please make sure to refer to the provided values ​​for compensation when outputting and printing.
2. The effect of the color of the bottom of the paper;
3. The influence of black ink. In general, the ink of SWOP standard is lighter than the color printed in Asia. Please be careful;
4. Gray balance adjustment;
5. The visual error caused by the different reflective conditions of the used ink and paper.