Digital BW, The Print

> When might one not want to use relcol in these instances?

Steve,

In color work, I probably use RelCol as much or more than perceptual, 
but it varies by image.  I will soft proof each rendering intent to 
see which looks the best initially, then decide.

RelCol is often best when there are few out of gamut colors.  In 
these cases, the in gamut colors are left pretty much alone and the 
out of gamut colors are remapped to the closest printable color in 
the output gamut.  RelCol changes the relationships between colors, 
but the accuracy of the in gamut colors is preserved.  If there are a 
lot of out of gamut colors, RelCol can often look lousy, since the 
relationships are all wrong, and the eye is pretty sensitive to 
relationships, especially when it comes to "memory colors", such as 
skin tones, neutrals, sky blue, green grass, etc.  

Perceptual is often a good choice when there are a lot of out of 
gamut colors.  Perceptual will attempt to preserve the relationships 
between colors, at the sacrifice of absolute color accuracy, so all 
colors are remapped to some extent.  Sometimes, there are big shifts 
in overall brightness level and saturation as a result.  

In either case, I will usually soft proof both, choose the one that 
works best with my current image, then make final brightness and 
saturation corrections before printing.  This describes my color work 
flow.

For B&W, I almost always use Perceptual.  I don't have to worry about 
color and saturation relationships in monochrome printing, and I do 
want to maintain the relative relationships between shades of gray.  

Lou