The file pre-flighting process is performed in two stages. We use PitStop Pro – specialized software for checking and correcting PDF files, which has a built-in algorithm for automatic checking of particular parameters. Afterward, your files are being checked by our prepress experts. This is mandatory step as only a prepress professional can find incompatible with the perfect printing specific errors and discrepancies.
I. Automated control and verification with software
1. The page format and if there are different pages;
2. Chromaticity – if used colors are different from CMYK;
3. Presence of texts or other graphic elements near the knife (preferably 5 mm but not less than 3 mm);
4. Used fonts;
5. Photo resolutions in dpi/ppi;
6. Text overprint;
7. Inking/Ink coverage (for 1 color book over 100%, in CMYK – over 300%).
II. Manual check and correct by an expert (can’t be done by software)
1. Checking the actual format;
2. Chromaticity corresponds to the task/order;
2.1. The Pantones reference are equal with those indicated in the task/order;
2.2. Is the text 100% black;
2.3. If there is a grey text in CMYK (it is recommended to transform it as a percentage of black to avoid color shades)
2.4. Pages designed with color rectangles – the color mode is identical on all pages to avoid color difference.
3. If text or vector illustration is Converted to curves – the Pitstop does not indicate that it is near the cut;
4. If the book is stapled or sewn-glued/hybrid, there must be at least 7mm from the cutting edge/mark;
5. The fonts have to be embedded/integrated, we can do it if they are free/not paid;
6. Check the messages for a photo with a shadow, which also is a photo (if there is white on the edge it will make difference with the shadow);
7. For comics we check the format of the photos (jpg, bmp …) and their resolution in dpi/ppi;
8. Overprinting of black rectangles and texts positioned over images or colored rectangles;
9. Pantone overprint;
10. High resolution does not always guarantee good image quality;
11. Expanding/canvas photos and color rectangles to prevent from cutting/edge lost;
12. Coincidence the elements on the images and color rectangles in facing/double pages;
13. Color photos or rectangles/frames on the inside facing pages or between the book block and cover/frontispiece;
14. Page numbers are placed on the same place on all book pages;
15. Indexes in shapes and page numbers are the same and placed on the same place in some or all book pages;
16. Identical margins and block text on every page;
17. For required formats 170/240; 110/180 and some other formats within the limits, verification of the existence of a white margin/space on the outer edges (we can’t put the photo to the cutting edge);
18. If there are photos with frames – check if all frames are identical (colors and dimensions);
19. Does the image fill the frame? (does it touch the edges of the frame);
20. For the color body – whether the black and white/BW photos are in CMYK;
21. Moiré – the printed pattern of dots can interfere with the image (when we scan/shoot objects/photos with cloth texture);
22. Elements that are on the crease or the gutter;
23. Barcode and/or ISBN of the inner body and the cover must be identical (if applicable);
24. Barcode chromaticity (black and white BW are preferred to avoid color shades/shadows);
25. Date and existence of completed print information (if applicable);
26. White margin/ractangle between second and third cover for gluing of the back properly;
27. A tiny serif font on solid color or photo may become illegible/unreadable;
28. Bidding/enlarging on all sides (inner too) when the body is with spiral.
Other preflight checks can be carried out according to the specificities of the job.
Please do not hesitate to contact a sales representative if you have any questions about preflight checking and setting the layout.