Often times an art reproduction image that's been captured absolute colorimetric will fit entirely inside the gamut of the desired paper, in which case I can print using absolute colorimetric and get an excellent match that pleases the artist.
But sometimes almost the entire image fits inside the paper's gamut with just a few regions of very saturated dark colors that are below the gamut of the paper. So, most of the image is an excellent match when printed absolute, but those saturated dark colors get mapped to the closest point on the paper's gamut (a mostly upward vector when viewed in ColorThink Pro). That vector makes those colors vibrant, but too light in relationship to the colors around them. Maintaining the luminosity of these colors often seems to be more important than the chroma or hue.
What strategies would you guys suggest for dealing with those few regions of out of gamut saturated dark colors?
Here's what I do currently in these cases: in Photoshop, with the image in BetaRGB working space (slightly larger than AdobeRGB but not all the way out to ProPhotoRGB), I create a solid color layer that's got a and b values the same as the paper's black point, but is a few L values darker, then I use a luminosity mask on that layer to select from that L upwards, trailing off in a gradient at 15 to 20 L above the paper's black point. This gently shifts the image's dark colors down and in towards a point just below the paper's black point, so when they get mapped absolute to the paper's gamut they end up slightly darker and not quite as vibrant, but with their luminosity relationships better preserved. I guess what I'm doing is like a manual black point precompensation in working space in preparation for an absolute mapping into printer space.
This works, but it's a pain. Is there a better way?