In the photo below, you can see how the color is darker and duller in the finished book (left) than it is in the press approval proof (right) provided by the printer. The cover was printed offset (10pt C1S, 4/0) and finished with luxury matte coating.
The printer always tells me that matte coatings will make the color darker, and it is useful to consider this side-by-side comparison. The cover stock is not as bright white as the proof stock. The cover stock is warmer (more yellow). So, some color shift is due to the difference in the stock.
On screen the image looks very bright (yes I know the screen doesn’t give an accurate color match). I had already made the image brighter and a bit more saturated to come closer to our expectations from the screen. I’m glad I did as the printed cover stepped it back down again.
Design note to self: Remember to think ahead and account for the likely difference between press proof and actual printed results.
Possible strategies: pull back the yellow 5%-10%, increase brightness and saturation, and in some circumstances pay for a proof on the actual stock for a better proof to begin with.