Print designers are particular about quality. Paper type, color profiles, kerning, etc.; every detail counts in creating a polished final product. But there’s one detail that doesn’t make the difference it should.
Generally speaking, designers use TIFFs (containers for high resolution image files) when designing with photographs because the TIFF file format maintains the full quality of the image. JPEG is a file format that was created to compress images into significantly smaller file sizes in order to make them more flexible for things like use on the Internet. The difference in file size is substantial. For example, exporting a raw file taken on my digital camera as a TIFF created a 18 MB file; as a maximum size JPEG it was 2.6 MB.
The relationship between TIFF and JPEG is similar to that of a CD and an MP3. They’re both reproductions and the quality difference is so slight that it’s indiscernible. I would argue that unless you are making a poster-sized enlargement, a JPEG file is perfectly suitable for offset printing, provided that you follow a few guidelines:
1. Start with a high quality image. If the image you receive from the photographer isn’t high enough resolution or quality, no file type can help you.
2. Be careful with your saving. JPEGs use lossy compression, and each time it’s saved with the "save as" function in Photoshop, you lose quality. A good thing to watch for is the "JPEG Options" screen which asks you which quality level you want to save at. You should minimize the occurrences of this screen, and if it does occur, save at the maximum resolution. It can be helpful to maintain the original version of the file from the photographer in case something happens to your working copy.
3. If you have added text or vector objects to an image in Photoshop, don’t use the JPEG format. TIFF and PSD files retain these objects sharply. JPEGs don’t.
4. Don’t expect transparency. If you have an image with a transparent cutout, a JPEG will not work for you. Try using a PSD file (which integrates well with InDesign) or an EPS.
Following these guidelines and using JPEGs instead of TIFFs where possible can make your layout files much less cumbersome to work with on an everyday basis, and much easier to export and share as well.
Read more JPEG myths and facts here …