Clean colours on Epson 9900?

[wonderings]

We had a new Epson 9900 installed a few weeks back with a Fiery XF RIP. I am really impressed with the whole package and learning a lot as I go. Our past machine was a Epson 10600 UltraChrome, it served us well for 10 years or so with only one call for repair. We did not do much with it RIP wise, it was plugged into an old Harlequin RIP that powers our CTP. Basically drop the file and print. When going through some of the settings and exploring the RIP I found an option under Colour Optimization "clean colours". I had already set black to be as inkjet black and it was noticeably better with the blacks. What is this "clean colours"? I tried googling it but found nothing but ways to clean printers and other things. Is there a specific situation where "clean colours" would be used?

 

[Correct Color]

When you make a trip through L*a*b* (or XYZ, in the case of Fiery) sometimes primary colors that go in as clean can come out with a "scum dot" of some other color in them. A notable example is a blue scum dot in yellow.

Also if you're converting from one CMYK space to another, all your pure blacks -- such as type -- will be converted to four color.

"Clean color" is designed to fix that. However, note that every RIP has some similar feature, and in my experience, for inkjet printing in particular, they create more problems than they solve. In fact, in ten years doing color management and printer profiles for large format printers, I have never once left any such "feature" activated.


Mike Adams
Correct Color

 

[karenmn]

I found if I am using solid or PMS colors and they come up flat and/or dull, clean colors will (sometimes) brighten them up and remove some of the "scum dots" as Correct Color mentioned.

 

[David Milisock]

When you make a trip through L*a*b* (or XYZ, in the case of Fiery) sometimes primary colors that go in as clean can come out with a "scum dot" of some other color in them. A notable example is a blue scum dot in yellow.

Also if you're converting from one CMYK space to another, all your pure blacks -- such as type -- will be converted to four color.

"Clean color" is designed to fix that. However, note that every RIP has some similar feature, and in my experience, for inkjet printing in particular, they create more problems than they solve. In fact, in ten years doing color management and printer profiles for large format printers, I have never once left any such "feature" activated.


Mike Adams
Correct Color

I hear you

 

[Tommyjt]

No Title

This is directly from the Fiery XF help menu. It's just as Correct Color said.