Post processing photos for offset printing can be a very difficult task, especially when maintaining accurate and pleasing skin tones is a concern.
First, a note of warning
Unfortunately, it seems that Adobe temporarily turned off all print (non-RGB) proofing profiles from Lightroom, apparently due to software issues. (Reading software version history, I was able to find when this feature has been added to Lightroom but not when it’s been officially pulled) However, you can use the proofing tools in Photoshop until ‑hopefully- a fix arrives for Lightroom. So all is written here is basically true for Photoshop.
Softproofing workflow in Lightroom
My workflow in Lightroom/Photoshop, consist of setting the CMYK output intent same as what my print house uses, which in my case usually is Coated FOGRA39 (ISO 12647 – 2:2004), and soft proof using this profile. I also enable “Simulate paper & ink” option so I can see how much my deep shadows and highlights will be negatively affected in print, and then I can adjust the shoulders of the image histogram to regain some of that lost contrast. Because it’s easy to make the mid tones too dark, I usually drag the slider separating shadows and darks to the left, so I can burn only the darkest shades, without affecting darks. From my own personal experience, when an artwork has some deep black and strong highlights in some areas, it looks contrasty, without actually creating a high contrast photo with harsh mid tones in areas you might not like to have, like skin tones)The result on screen and with soft proofing turned off will look like a contrasty image with lots of over exposure in highlights and no detail in shadows, while in offset printing process ‑which contrast is less- it will look more natural. This is not a very difficult workflow for landscapes, architecture, and still life photography, but when it comes to human face, work can be more complex due to subtle colour shifts in skin tones. Also, increasing contrast makes harsher skin tones and emphasises skin imperfections. That’s why I usually increase exposure and decrease contrast and red hues in faces in lightroom, and do the final adjustments later in Photoshop , to negate the effect of adjusting the scene for offset printing output. I’m sure there are more advanced and scientific workflows out there to create more accurate and controlled output. As I’m exploring this subject and studying more, I will post about it later.
Softproofing inkjet printers, and photo print store’s dye-sublimation printers
You can also use soft-proofing to simulate your output for inkjet photo and dye-sublimation printers. I contacted Ted’s camera store in Canberra, Australia where I live, and the friendly and professional personnel provided me with their dye-sublimation printer profiles. Taking it little further, I even studied the possibility of finding the printer profiles for Kodak kiosks for fun, but due to variations in models in each store found it more difficult.