Horizontal lines texture in photos
Hi, I am preparing a book for publication, and my most recent proof arrived with a strange horizontal lines texture in most of the photos.
I have looked for a pattern here, and can't find one. There does not seem to be any relationship between which images have the texture, and the effective dpi of the images. No texture is visible in the print-ready PDF processed through lulu.com. Most of the same images had this texture, if not as heavily, in my first proof copy, but it's not completely consistent.
Any suggestions are welcome. For what it's worth, I'm a professional graphic designer, so feel free to get technical with me.