I create book covers for a very small press. I could link to the press website but it might be considered self-promotion, so I won't. I create them in Photoshop, and drop the jpg outputs into an InDesign template that comes from the on-demand printer (Lightning Source). I always make the jpgs CMYK (in Photoshop) before I start working on them. InDesign then puts out a PDF for the printer. So far, no one has cared how closely the printed covers match the originals (almost always photographs). All the authors have loved their covers. There's never been and won't be a client who requires matching a logo or corporate color or anything like that. Right now I'm working on a cover and I have gotten to a shade of red that works well -- by trial and error. I'm worried because if the printed version drifts very far from what I see on my screen I don't think it's going to work. It could tip into something muddy. I have no control over the printing process. All I can do is wait for a physical proof of the book (and an e-proof (PDF)) and if it looks OK, the publisher approves it and that's that. Resubmissions are expensive for a small-volume press. I'm sure that one of these days (we do 3-4 books a year) I'm going to create something I like, the author likes, the publisher likes, but that we're not going to like what we get back from Lightning Source (and it won't be LS's fault -- I'm not saying that at all). My question is: is it worth getting a calibration setup for my Dell U2711 (and/ or rMBP) to calibrate for RGB even though I'm putting out CMYK? The publisher is completely willing to spend the money, and I like the idea, but I'm not sure how (or even if) I can calibrate my monitor to show me what I'm going to see after Lightning Source takes my CMYK PDF and prints it on whatever commercial printers they use. As I said, everybody's been happy so far. But the world being what it is, sooner or later I'm going to have a color fail. And I'd like to do whatever I can to make that unlikely. I was thinking of the Datacolor Spyder4Elite S4EL100, but I'd be grateful for suggestions.