Necessary inspection before prepress output
when you prepare electronic materials for prepress service providers or printers, be sure to check the following contents to ensure that various problems that may be encountered to ensure the successful output of your electronic documents have been fully considered
what is prepress inspection
preflight is a noun borrowed from the captain's inspection procedure before the aircraft takes off. It means that the electronic document after pre press inspection will definitely be able to be correctly converted into graphic output, and it can make rip work effectively when it is output to the film. It is also a step discovered before occupying prepress operators, materials and equipment. After graphene was discovered in 2004, it quickly triggered a worldwide research hot topic. There is no need to spend money and time making 6 films or 6 printing plates when only 4 films or 4 printing plates are needed. Prepress inspection is a process of completely analyzing a designed digital printing activity no matter what output equipment is used. It is a necessary step to find any incompleteness or loss of electronic documents and characters, inappropriate or ignored chromaticity, insufficient bleeding, wrong page numbers, improper color separation, potential binding problems or inconsistent images before printing and outputting. Just the most troublesome problem of character errors is enough to prove the necessity of prepress inspection. Prepress inspection includes many aspects. The following are the most common problems that prepress operators may encounter:
who should be responsible for prepress inspection of printing
is prepress inspection performed by prepress service providers/printers or customers? The question that is still being debated concerns who will pay for the inspection. Considering the ultimate interests of prepress service providers, they should establish their own prepress inspection process and cost payment standards. On the other hand, prepress service providers also have reason to expect the drafters of electronic documents (1) to provide a complete document that can be run within a reasonable rip time (2) to provide necessary information so that the document can be run effectively (3) to provide methods and ways to quickly contact in case of problems
however, not all drafters of electronic documents know how to comprehensively establish a printing activity that can meet the effective output standard, and also consider the printing requirements. At the same time, they do not know the characteristics of the final file output device. Similarly, although designers may be very familiar with the design principles of balance, color, consistency, white space and proportion, they may not be familiar with technical problems such as overprint. Therefore, prepress inspection should usually be handled by professionals
it is necessary to establish communication channels between customers who want to export electronic documents conveniently and printers who want electronic documents to be complete and correct, especially in terms of the time and money spent on Printing correct output. For example, who will correct the document? Who will pay for the inspection? Since formal prepress inspection takes a lot of time, in some cases, customers may be willing to pay for this service
however, prepress inspection should not be started after the customer has delivered the disk. Some prepress inspections should begin with the establishment of electronic documents by customers. As part of the prepress inspection results, the customer should provide a proofing and proofing draft with the printed electronic document. At least, a notice list should be attached with the electronic document to remind the prepress inspectors of the relevant character information and other relevant documents other than the whole page layout document
on what media do you transfer your documents
□ electronic transmission □ floppy disk □ magnetic tape
□ portable hard disk □ magnetic disc □ CD ROMs □ DVD (if the packaging is given a recyclable design digital video disc from the beginning)
it should be confirmed that the file format you transmit is compatible with the computer system, and can complete the actual design, color correction, page numbering and output in the computer system. Make sure your disk is protected and only the files needed for file output are delivered
do not use the only copy of your document for transmission, because the readable and writable media (such as optical, magnetic tape, zip, Jaz) are prone to unpredictable errors, so it is best to format the media before copying the document, then copy the disk, and then transfer it to the prepress service provider
is the page number set appropriately
make sure that the output device has been set correctly. It includes page size, typesetting method, book margin, bleeding requirements, overprint, etc. Certainly a folding method allows folding of pages of different sizes, and the folded pages are always smaller step by step
are all necessary output files provided
load your electronic document in the document format required by the prepress service provider or the printer separated by air gap. If the prepress service provider or printer has required your documents to be delivered in a document format acceptable to them, you should not deliver documents in EPS or other formats. For the limitations of various file formats and some tips in application, see "file formats" in the technical appendix
if you are preparing electronic documents, you should confirm that you have saved all images and printed documents in a document format that can be used by prepress service providers or printers, and provide their original copies and copies. In this way, when the image or printed document is lost, it can still be found on the computer monitor, but it will be output at low resolution, which looks distorted or distorted. The printed documents and application documents should also be placed in the same subdirectory, so as to ensure that all printed images in the page layout document have been established
error prone file formats such as pict and WMF should be avoided in output. Otherwise, even if the file is correct, there may still be problems in converting the format
for those documents that have adopted FPO or opi/apr format, if DCS printing grid is used, it is expected to be in 2025 format, documents of all five images (yellow, magenta, cyan, black and synthetic color images) should be provided
in the prepress inspection or the requirements of the prepress service provider, it should be indicated which low resolution images need to be replaced with high-resolution versions
is the original source of the image provided
if the prepress service provider or printer has made a request in this regard, they should provide a printed proof or proof in a document format acceptable to them
have the characters used in printing been marked
the name, version, quantity and font (true type or post script) of all characters should be indicated. Make sure you choose the real characters from the character menu (such as Garamond BOLD), rather than selecting a style such as "bold" from the style menu. At the same time, consult the prepress service provider or printer for the requirements of relevant character documents. In some rips, the mutual interference between true type and type 1 post script characters will cause character substitution and string bits
does the prepress service provider or printer provide image scanning
all images that require prepress service providers or printers to scan should be clearly marked with information about cutting and final size
have all colors been converted from red, green and blue to yellow, magenta and black
if the image is not converted to yellow magenta black mode in your electronic file, the printed image may be black-and-white or have unacceptable color deviation. Remember to name all colors in the document, and the image colors designed and introduced in the image processing program should also ensure that the same name is used exactly
unless you plan to print small color blocks or common colors with spot color ink, you should definitely use the Yellow magenta black setting mode for all colors. As long as the whole page layout program allows, the small color block area should also convert the color mode
is bleeding printing possible when needed
make sure that all bleeding printing is extended to the edge of the page as required by the printer. It is very convenient to realize image bleeding in the whole page layout program, but it is relatively time-consuming and expensive in printing
has the original proofing of the document been considered
black and white laser printouts or color samples of the final documents shall be delivered. If the document is transmitted to the printing service provider through the line and modem, it should be sure that the laser printing sample sheet is faxed or the proofing sample sheet is transmitted at the same time. Confirm that the sample is obtained from the same electronic document delivered to the printing service provider or printer
if the page is too large to print the original large sample with the same size as the actual size, be sure to mark the reduction ratio on the sample
the color separation sample (in black and white form) shall be printed on the laser printer. In addition to providing color samples to printers, color separation samples should also be provided to ensure that each color separation sample is correctly marked with color. And check whether the color separation of the color separation sample is correct and the color number of the color separation
if a black-and-white composite sample is provided, each part printed in different colors should be clearly marked
have all precautions been marked
the name, address and contact should be clearly written on the disk, portable media, printed proofs and samples. In short, all documents or media delivered to printing service providers or printers should be clearly marked
at the same time, a list of all documents or media you have transmitted should be sent to the printing service provider or printer
ten main problems in prepress inspection/output
1, character error or loss
2, image chromaticity problem
3, binding problem
4, incomplete or inoperable file
5, in the whole page editing program, the size of EPS and TIFF files is too large
6, small color areas are not converted to the correct color mode
7, file format (may cause output confusion)
8 TIFF files are not converted from red green blue mode to yellow magenta black four-color mode
9, insufficient bleeding
10, and the original used storage media is not formatted
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