6 colour

[bob_5793]

Hi
I have been asking about 'channels' supported on printers, and if printers with 8 head capability can support CMYKLcLmOG, the thread is here:

http://www.signs101.com/forums/showthread.php?t=92427

I am curious to know how the Lc Lm channels are handled, OG are separate primary colours, which I assume are handled through ICC profiling, and the application separating values into the correct channel, but does this apply to the Lc Lm, as these are just a 'subset' of CMYK, not separate Primaries, where in the process of getting a PDF image from the application and onto the media does the Lc Lm get its values, in the RIP or in Firmware in the Printer, or does it occur even earlier (ie withinsay Indesign).

 

[P Wagner]

In a RIP-driven workflow, the media profile defines the ink splits (when to use light channels cm, and trandition to dark channels CM). You are correct in that the light/ diluted inks are extensions of the CM channels.

 

[Rooster]

In a RIP-driven workflow, the media profile defines the ink splits (when to use light channels cm, and trandition to dark channels CM). You are correct in that the light/ diluted inks are extensions of the CM channels.

Usually the ink splits are separate from the profile and controlled with curves. One for each of the full strength and one for the diluted to set where they cross over and how they apply ink. They are then treated as a single ink channel.

The LcLm is there solely to reduce the visible dot and provide a smoother looking print. If it's profiled as a separate channel then it won't know to only print at 50% and below (or wherever you set it) of that ink channel's density.