HP Indigo - Navy Blue Shadows Gamut Clipping?

[Sherbert]

Morning all,

Mostly all of the schools in the UK have Navy Blue Sweaters as uniforms.

When we print these we get problems with the shadows in the sweater. You can also see this while emulating the Indigo Colour Profile in Acrobat Pro Output Preview.

I guess there isn't a panacea for this? It'll be a manual tweak of all images to bring the levels down right?

See attached for pictures.

 

[Stephen Marsh]

Blues are often a problem in CMYK when compared to the RGB original. Where are you performing the conversion? Is the conversion direct from input RGB to Indigo device CMYK (what rendering intent and black point compensation settings)?

Have you tried converting to say F39 or GRACOL or SWOP CMYK first, then to Indigo device CMYK (what rendering intent and black point compensation settings)?

Can you post the Indigo device profile?


Stephen Marsh

 

[Sherbert]

Thanks Stephen,

These details are from the ticket template on press. This is the settings it'll be ripped with using 4c.

Normally our files are PDFs, which are imposed and dropped into a hot folder. (PDF> Quite Imposing > Pitstop [If Needed] then Ripped.)

This is the standard way the presses are setup. I've spoken to a couple of people at HP about colour management on press and they are never much help.

ICC Here: http://dl.dropbox.com/u/19812412/Print Planet/HP5000GlossExp05.icc

In this instance, the customer has converted the files to CMYK in photoshop before placing them in Indesign and outputting to PDF.

I would suggest to our customers that you don't convert to CMYK before using Indesign and let Indesign do the conversion.

 

[Stephen Marsh]

You state "In this instance, the customer has converted the files to CMYK in photoshop before placing them in Indesign and outputting to PDF."...

However looking at your RIP settings above, there is no assumed CMYK input profile if the input data is four colour. I would then presume that any* CMYK data is presumed to be in the Indigo device CMYK space, when I doubt that would be the situation.

Try putting in Fogra 39, GRACoL or SWOP as the input CMYK, so that a common press space is transformed into the Indigo device space. I would hope that this would lead to better results. I would also see if using Black Point Compensation helps.

Please post back and let the list know how things turn out, it is always good to get feedback!

*Not sure if ICC colour profiles are honoured or ignored, or if multiple input profiles in PDF files are honoured, or if a PDF output intent ICC is honoured etc.


Stephen Marsh

 

[Sherbert]

Thanks Stephen,

I am pretty sure BPC would definitely help in this situation. Kind of amazed it isn't on as default.

Normally we output indesign files to Indigo ICC profiles, obviously our customers can't always do this.