Shadow Densities

[Franknater]

Do any of you have a maximum for shadow densities such as we have on sheet-fed presses? We have a new press that can easily run 300 total ink in the CMYK. If you have shadows that would print 360-380 range, would that cause a problem? What are some of the problems you encounter as far as color (not relating to ICC or other profiles)?

Frank

 

[seejay]

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.

 

[PeterA]

Re: Shadow Densities

We print a lot off Direct Mail for Wine Clubs - wine bottles are usually retouched above the 330 TAC of the profile - We tried Alwyn colour to alter the Tax and it did very well

peter

 

[cosmo]

Re: Shadow Densities

Frank, you shouldnt really go over 320%, main reason, your ink wont dry.

 

[LoneGoose]

Re: Shadow Densities

Frank, you mean are there maximum coverage values for toner-based presses?

Yes, they recommend 280% on the NexPress - otherwise the toner doesn't fuse properly and scratches (sometimes falls) off.