CHROMiX

Strange gray to black

I’ve got an HP5500uv combined with ONYX PosterShop 5.6, and ProfileMaker 4.1 with an i1.

I’ve made a base linearisation, and set my maximum ink on 300%. After this, I’ve printed an ECI2002 patch and read it with my i1 in profilemaker.

Then I calculate it with GCR3, Blackstart 30% with an Logo Chroma plus rendering intent.

When I make a print with this combination, the shadows has a strange cast, and goes suddenly over into black. It happend if you render with relative colormatric, but I don’t. I use Perceptuel. A sample of this strange gray to black-problem can be seen on: vandenbrom.com/print.jpg

Could this be a problem of my colorprofile calculating? Or what else could do this strange problem.

HELP!!!
:unamused:

It’s posterization - or stepping of tones.

Are you using a RIP? If not and you are printing straight to the printer form your application then you need to treat it as an RGB device (yes, really). Gretag Macbeth has RGB targets so print one out and read it in.

Otherwise…

How did you arrive at your ink restrictions and ink limit? And how did the taget print look before you read it in?

Steps you need to get a good profile:

  1. Ink restrictions: test and set limits for each of C, M, Y and K.
  2. Linearize.
  3. TAC: Print out a test to find the total area coverage (or TIC - total ink coverage) for your media. Set that value.
  4. Print the ICC profile target and check it. If there’s any puddling or other artefacts, then start from step 1 again. If your target is not perfect then neither will be the ICC profile.
  5. Test, test and test the profile on images / file types that you would normally use.