Gamut Checking

[arossetti]

In a windows environment how does one check to see if a CIE LAB value is inside an ICC profile?

 

[avid_mike]

It depends on what device you have and what software you have. I have an i1 Pro with Color Picker, so I just input the LAB value in and it tells me if the color is in gamut or out and what the CMYK breakdown is with the ICC profile selected.

 

[arossetti]

It depends on what device you have and what software you have. I have an i1 Pro with Color Picker, so I just input the LAB value in and it tells me if the color is in gamut or out and what the CMYK breakdown is with the ICC profile selected.

Doesn't look like X-Rite sells Color Picker anymore. Have they replaced it with a different peicce of software? What you describe is exactly what I'm looking for.

 

[avid_mike]

It was part of the Profile Maker 5 suite. Some of the apps require a dongle, but other ones like Color Picker mostly worked without on, you just couldn't save a whole pallet of readings. Here is the link on X-Rite's page. Again, it will have limited functionality without a dongle, but Color Picker will work. Contact me if you need help using it. Great little piece of software. We use it every day in my shop.

ProfileMaker v5.0.10

 

[Deleted member 16349]

In a windows environment how does one check to see if a CIE LAB value is inside an ICC profile?

I have a strong suspicion that even if a colour is supposed to be within a gamut, it might not be obtainable. Part of the problem, I believe is due to the fact that with real pigments used in printing, the reflectance spectrum for any one channel, such as printed magenta, exists all across the entire visible spectrum. This makes it impossible to make adjustment that only affect one area of the spectrum when trying to obtain a colour.

The simplest and most well known colour that is supposed to be within the gamut of CMY but is hard to obtain is black or different shades of gray. In the darker tones it is not obtainable but as the tone goes lighter it seems to get closer but usually never actually hits the target. Probably a big frustration for the G7 types who are trying to get to that value. Close but usually not exact.

Black is no different than any other colour and it is very likely that there are very many colours that should be within the gamut but can not be obtained for the very same reason.

What does this mean? I can mean that even if some software says that a colour is obtainable, it might not be.

 

[arossetti]

I have a purple, L*10, A*35, B*-38 which the closest I have been able to get to it is a DeltaE76 of around 20. I'm just trying to find out what is causing the issue. Printer or destination profile. My GRACoL wedge is inside 12647-2 so I assume it is out of gamut but it is also a pretty simple CMYK build.

 

[avid_mike]

Closest I could get with the Gracol 2006 coated ICC profile is a deltaE of 10 with a break down of 76-100-0-49. What ICC profile are you separating to? That is a pretty dark purple.

 

[gordo]

I have a purple, L*10, A*35, B*-38 which the closest I have been able to get to it is a DeltaE76 of around 20. I'm just trying to find out what is causing the issue. Printer or destination profile. My GRACoL wedge is inside 12647-2 so I assume it is out of gamut but it is also a pretty simple CMYK build.

What's your ink sequence?

 

[arossetti]

This is off a digital toner based press. Sequence is Y-M-C-K.

 

[avid_mike]

What ICC profile are you printing to?

 

[arossetti]

Thats where it gets tricky. I'm printing to a lowest common denominator of my 3-presses, target being GRACoL_2013. So we have a hybrid in-house standard.

Shall I upload my ICC?

 

[avid_mike]

Well, a purple with a L value of 10 is really dark. Not sure where you are getting the LAB values from, but it just may be out of gamut period. In that case, I would try and get the hue dialed in as close as you can, understanding that the saturation will be less. Where are you located? I might be able to call you and review.

 

[gordo]

This is off a digital toner based press. Sequence is Y-M-C-K.

Curious, can you change the toner sequence? If you can does it change the colors it prints?

 

[arossetti]

I am unable to change the sequence. I'm doing some research into Chromix Color Think as a software solution.

 

[avid_mike]

I have Color Think. Not sure it will do what you are asking about but Pat Harold or Rick Hatmaker there can help you.

 

[rich apollo]

You can still download the entire ProfileMaker toolkit. It won't run on a Mac OS newer than 10.6.8, it will still run under Windows.

ColorThink is a great way to visually examine why a color may not reproduce. I've uploaded an image of your target color plotted against the gamut of GRACoL_2006. In the screen grab, your target color is the white dot. It's really dark and really saturated.

You're not going to be able to print that color.

 

[arossetti]

You can still download the entire ProfileMaker toolkit. It won't run on a Mac OS newer than 10.6.8, it will still run under Windows.

ColorThink is a great way to visually examine why a color may not reproduce. I've uploaded an image of your target color plotted against the gamut of GRACoL_2006. In the screen grab, your target color is the white dot. It's really dark and really saturated.

You're not going to be able to print that color.

Excellent thank you. It's nice to have a visual to show a customer. I'm running all my color management software on a windows 8 pc which won't install the ProfileMaker software. This is why I started to look at Color Think.

 

[Bill W]

Greetings, you can use the attached file to check a color in ColorThink grapher. Just open in excel, or any text editor, and replace the labxyz values with the values of your color, then add to Plot Items box in ColorThink grapher.

 

[arossetti]

Greetings, you can use the attached file to check a color in ColorThink grapher. Just open in excel, or any text editor, and replace the labxyz values with the values of your color, then add to Plot Items box in ColorThink grapher.

Awesome, thank you!