In fact, in most publications, color separation proofs are no longer needed. Only one SWOP sheet or pre-proof proof sheet is needed.
If the publisher provides color separation proofs, it should include four monochromatic proofs, a tricolor proof, and a four-color proof.
All proofs and separation proofs should match each other and keep the same amount of ink.
Whether it is a model, pre-proof proofs, or color separation proofs, it should contain the name, address, and telephone number of the prepress service provider and, if possible, the name of the contact person at the time of the problem. A cover tag can be used to describe the above information in detail.
Each publisher will specify the number of proofs or color separations needed.
Samples and separation proofs should not have any traces of the past, nor should they be damaged. This may affect the reading of the color scale by the densitometer.
Two-color and monochrome proofing In the process of submitting proofs, each model or pre-proof proof should be submitted with a single color or two-color film. According to the description of the parameters, individual publishers' ability to accept proofs, screen lines and the number of proofs needed to be reviewed.
Pre-proof proofs SWOP recognizes the use of analog and digital (half tone and non-half tone) pre-proof proofs that conform to the manufacturer's SWOP application data sheet. SWOP cannot guarantee the accuracy of any pre-proofing system. The ultimate user is responsible for determining whether any given system fits into their workflow.
Manufacturers of pre-proofing systems must list a SWOP application data sheet to guide the user to produce pre-proof proofs that look as close to the SWOP as possible. Application data sheets for each of the traditional and digital pre-proofing systems can be obtained through SWOP.
The application data sheet lists the manufacturer's recommended density values, dot gain values, color sequences, colorants, and substrates to ensure the best match to the SWOP model.
SWOP has established a method for checking proofs and manufacturers' application data sheets. Users can contact GATF to obtain the necessary procedures for confirming the process.
The proofs used must be very similar in appearance to the SWOP. The proofer should ensure compliance with the appropriate SWOP application data sheet.
Note: When the proofs are made in accordance with the SWOP application data sheet provided by the manufacturer, it does not necessarily mean that they can be completely matched with the SWOP models. In addition, it should be noted that different pre-proofing systems do not exactly match one another.
The SWOP Calibration Toolbox is available from GATF, including Certified Press Proofs. Moreover, an electronic file for illustrations and test strips in the SWOP standard toolbox, ISO 12640, is also available from NPES. These tools can be used to determine the relationship (subjective or objective) between the Certified Press Proofs and the proofing system used.
Pre-proof proof cover labels Pre-proof proofs The outer envelope of the proofs should be accompanied by a cover sheet or label strip to record the proofing products or systems used, as well as the name, address, and personnel of the prepress service provider.
The tag should also contain information about the manufacturer's application data sheet.
All pre-proof proofs of the control strip should contain a color standard. The color scale should be present on all half tone proofs (analog or digital) with 133 lines of screen lines. All color patches should contain solid, 25%, 50%, and 75% shades for each printing primaries, solid overprint colors, and at least one gray balance color block (cyan = 50%, magenta & yellow = 39%). It is also recommended to include two-color overprint blocks with dots at 25%, 50%, and 75%, respectively. This color standard should be in the form of a manufacturer's color control bar, such as GCA/GATF Proof Comparator or GATF/SWOP Proofing Bar) or equivalent digital form. There should also be an exposure control element in place.
Solid density and color pre- proofing density and colorants are set based on the SWOP Hi-Lo Color Reference. Due to different processes (eg film coating, coating, color sequence and colorant, etc.), the parameter values ​​of the pre-proofing system will differ from the high and low color reference values ​​and should be explained in the application data sheet.
The goal of dot gain and gray balance tone reproduction is based on the SWOP model. The imaging characteristics of different technologies can result in slight differences in color and tone reproduction, but the results must be acceptable and must be kept closest to the visual appearance of the SWOP model. Total Dot Gain and Tone Value Increase are listed in each manufacturer's application data table.
It is important that pre-proof proofs get the gray balance as close as possible to the SWOP printed proofs.
Users of color sequence using pre-proof materials should be aware that manufacturers of these products tend to specify a specific colorant application sequence. This order may be completely different from the order of print proofing and print production. (To be continued)