Preflight checking in InDesign

The term preflight check originates from the aviation industry where it is a standard procedure for pilots to go over a checklist before lift-off. Preflight checks (preflighting) for print documents have a similar idea in mind. They run through all the files you used in the document to see if they're missing, changed or anything else that might have happened to the file.

Back in the day, preflight programs or plug-ins gathered all used fonts before sending off your document to the printer. With the rise of PDF this process changed as fonts are included fully or in part in the PDF file. A (modern) preflight check checks all used images and fonts in the file, if the files can be found at their indicated locations, if they're in CMYK and if fonts are used and load correct. On occasion copyrighted fonts cause problems with being embedded in the PDF file. This also is checked in the preflight check.

• Preflight check on file opening
The latest versions of InDesign and Quark Xpress - InDesign CS2 and Quark Xpress 7 - check missing files when opening your document. This could also be called a - perhaps small but still valid - preflight check. The program will warn you if a file moved or is missing after last opening the document.



• Preflight check in InDesign
Click File > Preflight… in the menu to open the Preflight Check dialog screen. Here you'll find categorized sections to check your documents on errors and missing files.

A small warning icon  indicates problem areas.



If there are any files missing you can replace those from the Preflight Check dialog screen. If - for any reason - you can't send a packaged PDF to your printer, there's also the option to package all external files in one directory to send those separately with your layout document.



• Watch out for included PDF's!
As Adobe warns you about InDesign cannot check the ICC profiles, color spaces, or images for placed PDF pages or placed InDesign files. So make sure everything you place in your document through external PDF files is checked by hand in either the original file (in Illustrator or InDesign) or check the exported PDF (in Acrobat).

• But you're not done yet…
Although the automatic preflight check in InDesign sure comes in handy, it's not 100% complete. There are still a few things you should check by hand.

• Is the bleed correct? Does the size comply with the printers request.
• Are your color separations correct? No PMS colors mixing with your CMYK or the other way around.
• Are you exporting with the correct registration marks?
• Check if image resolutions are good enough (300 dpi for standard print work)
• Is the size of the document correct? Are you adding the bleed size to the document size?