Hey, eventually...
I haven't been able to find an overall setting in Photoprint yet... I'll keep looking.
Thus far, and I'm down to 85 (as I progressively do signs that are going further down the road...), things are looking better overall. I know, I know... No profile by eye... I'm gonna get a gizmo eventually - what do you use?
I agree with GraphiXtreme, modifying a profile is the last choice to make and can give unexpected results later on.
The overall ink limits are sometimes called MultiChannel ink limits and they are mixtures i.e. C+K+Red, and not just the initial CMYK ink restrictions.
In outdoor applications the initial CMYK ink settings are the most critical.
Too low and colors will be washed out no matter what.
Too high and the Multichannel ink limits will have to be cut back too far.
Either way, the ICC correction can give poor color output.
Get the initial ink restrictions good and the rest of the profile will fall into place easily.
Each media, each environment (and in reality each printer) will affect how much ink can be applied to the media.
We use an Eye One, DPT41 and DPT70
The Eye One is a handheld unit that takes a bit of practice to use and quite a bit of time to read large sample with, but works well.