Here at Four51, we recently had a discussion about best practices for Pageflex projects. The conversation revolved around the utilization of images, for print, in projects; how to maximize efficiency for screen display and web presentation while not compromising print quality. During this discussion, we realized that there are a number of misconceptions regarding this topic. After we were finished, I felt it would be a good topic for a blog post.
A question posed was the viability of TIF images vs. other formats. TIFs are considerably larger than any of their counterparts because they are not lossy. JPEG images, however, are lossy, so why would I tell you to use a JPEG over a TIF? Primarily because you should edit and work from a TIF, but for inclusion into your Pageflex project, you should save your TIF as JPEG. Do not destroy your working copy of the TIF image because you should go back to that for edits to the image. Repeatedly editing a JPEG will surely lead to image degradation, so work in the non-lossy format, but always save down to JPEG for project inclusion.
I want to add that I’m not telling you JPEG images are the best print option. Obviously, if you are designing the project in Adobe tools, you should stick with the formats best suited for those tools, like PDF. If you are working from a PSD embedded in your InDesign layout, work with PDFs.
I demonstrated the difference in file sizes by taking a 70MB TIF image and saving to JPEG with 233dpi and high quality output option and removed the embedded RGB color profile. The file dropped from 70MB to 230KB in size. The print quality remained unnoticeably affected.
I found the best and most concise definition of these two formats at Wikipedia. I think these definitions support my argument above.
A little food for thought: When you purchase a stock photo library for your print jobs, what format are the images you receive?