Re: Shadow Densities
In our experience, this is usually paper dependent. Higher grammage, better quality stocks can hold more ink.
Our problem has been with a small number of specific clients who run thier jobs on very light stocks 65-90gsm gloss coated, with very high CMYK coverage in shadow areas. these jobs caused us all sorts of problems, paper tearing, picking, set-off, marking in finishing ... the list goes on. The only way we could get the job to run was by slowing the press down to 1/2 speed - even our press supplier could only get marginally better results in a showroom environment.
We worked with the client to educate them on how to bring their TAC down, but they still have an issue with third party supplied adverts. Other jobs we can comfortably run with TAC in the numbers you are quoting - though we still try to educate clients to bring it down more in line with ECI recommendations.