Reply To: Image degradation on resaving from PSD to JPEG

It's worth noting that unless you explicitly set something else in PDF export, your images will be jpeg-compressed on export and will be downsampled if more than 1.5x your target resolution, which at the default 300 ppi for print means that any image over 450 ppi at the size it is scaled to in the layout (the “effective resolution” in InDesign terms) will be downsampled. It's just part of how PDF export works.

There are two schools of thought on this. One school says you should exactly size each image in Photoshop and place the resized copy in the layout. The other, more production-oriented view says place each one as a PSD and let the export-to-PDF function handle the downsampling, which in my experience works perfectly well for all but very high-end, critical print work. In either case, use the jpeg compression setting that works with your production needs, or turn off compression completely, in the PDF export dialog.

Placing a PSD is much more productive (“Edit Original” allows round-tripping to Photoshop for any needed tweaks) than first making a jpeg or flattened tiff and placing that in the layout. It can save many hours in the course of a week. Quality degradation with jpeg is far less of an issue than most people believe, but in any case is avoided by keeping the image in a lossless format such as PSD.