Not able to pront an off-yellow - no GAMUT warning

[fixitks]

Hi - I'm having some issues with gamut/proof and printing. In the first image, I have my proof setup to simulate my Canon Pixma ix6850 printer (using glossy paper) - so using the Canon iX6800 series GL2 (for Glossy paper).

In the second image - you can see the colour #E0Ef53 - a yellow-ish colour on the screen - and NO gamut warning (so I'm assuming in line with my printer profile, it should print ok?).

In the third image - you can see the colour #FFFF00 - pure yellow on screen - and a Gamut warning. So I'd assume that wouldn't print ok.

The fourth image is a camera photo of the print. Showing the E0E453 colour printing out in a wishy washy green colour (but did not trigger the Gamut warning). The FFFF00 colour however, which did have the Gamut warning, has printed our perfectly.

Have I misunderstood Gamut - in that if it flags in the colour picker, then it will NOT transform correctly from screen to print?

Thanks for any help,

Mark

[TheDigitalDog]

In a nutshell, ignore the out of gamut overlay.
In great detail why:

The Out Of Gamut Overlay in Photoshop and Lightroom

In this 25 minute video, I'll cover everything you need to know about the Out Of Gamut (OOG) overlay in Photoshop and Lightroom. You'll see why, with a rare exception, you can ignore this very old feature and still deal with out of gamut colors using modern color management tools. 

YouTube: https://www.youtube.com/watch?v=00O-GTDyL0w

High resolution: http://digitaldog.net/files/OOG_Video.mp4

[fixitks]

Thank you - that's a very insightful video and description of the GAMUT feature.  So in essence, the fact my printer is printing an off green instead of an off-yellow is nothing to do with GAMUT? So perhaps I have a dodgy ink cartridge (although it prints perfectly in full yellow) - but the other colour which appears yellow-ish on the screen, prints in an off-pale-green. Is that more likely to be the source of my issue? I've never noticed the issue previously, until printing a very specific design for someone.

Thanks again, and for the video - (btw, not that it matters, but it's Photoshop 23.4.1 on the PC I'm using).

Mark

[TheDigitalDog]

Lots of different devices have a different color gamut, nothing you can do to alter this. You can't fit a gallon of water in a pint container. 

[fixitks]

Is the point of a printer profile, not to help match what you see on-screen with the printed version though, or have I missed the point? If I'm off on a tangent, and should post in another forum, please let me know.

Thanks, Mark

[TheDigitalDog]

Yes, within the limits of the display color gamut.

No printer can print the full gamut of even sRGB as well. 

Like fitting round holes in square pegs.

[Test Screen Name]

A printer profile is a set of tables to convert colour. So, in theory at least, your RGB colour is converted to a CMYK colour, using the tables in the profile. That's where it stops being simple, because "renderng intent" now matters. There are three important rendering intent and the profile actually contains three sets of tables - so the colour conversion is entirely different. 

And... some printers don't print using profiles, so the profile is only there to give you a sense of how it will print - it won't be exact. This is certainly the case for your printer, which is not 4 colour CMYK. It has 5 inks. Even though two are different blacks, it means a CMYK profile can't give the full picture.

[Bob_Hallam]

Having the profile to compare would be great.  Glossy stock is a very generic term.   Most profiles are created for specific stocks, so If you have the paper and profile that's best.  Good printers on nice coated stocks from reputable manufacturers can easily cover sRGB color space.  As a matter of fact, the US  sheetfed Offset print standard gamut is larger than sRGB so it's quite possible to cover this space on coated papers.   Here's one example from Hahnemuehle, whose papers I'd recommend as excellent.   Where you can see your issue.  The yellow-green colors are outside the gamut of the profile.  So your gamut warning is accurate, just give perceptual rendering intent a try, to see how that yellow-green color is mapped back into the printer's gamut.  If it's acceptable, you're good to go.  If not I'd suggest trying a larger gamut printing process.  Epson printers with 12 or more colors will cover that gamut without a problem.  

[TheDigitalDog]

Good printers on nice coated stocks from reputable manufacturers can easily cover sRGB color space.  

Even YOUR gamut maps here show that isn't true. 

Please plot a printer next to sRGB where the printer fully encompasses sRGB. Otherwise, I'll stick to my statement that no printer can print all of sRGB. There are actual, visible colors IN sRGB that no printer can produce. 

Since this is a forum on color management, you might wish to rephrase your statement and use gamut volume to correctly imply that there are printer gamuts that are larger in some areas of color space, often by a lot, than sRGB. But the statement above and your gamut maps do not.

Good printers on nice coated stock cannot easily cover sRGB color space. Those are colorimetric facts your gamut maps clearly show. As a matter of fact, the US sheetfed Offset print standard gamut is not larger than sRGB in some areas of color space. 

[Bob_Hallam]

Andrew, my gamuts were not there to show the truth of that statement.  They were there to show the problem the OP is having and help.  Please do read.  In this thread, I'm helping the OP.  If you have a problem let's address that in another thread, please.  I've shown that statement to be true many times already.  You can go back and check. 

[TheDigitalDog]

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@Bob_Hallam wrote:

Andrew, my gamuts were not there to show the truth of that statement.  

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They show mistruths Bob. The maps and the sentences. Sorry, they are simply not correct in your context to the OP. 

It would again be useful to use Gamut Volume** which is a well-defined and agreed-upon way to express the size (volume) of the color space gamut of which again, no printer can fully fit into sRGB as you 'imply' for the OP who should be told the colorimetric facts here. 

**http://www.brucelindbloom.com

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@Bob_Hallam wrote:

  I've shown that statement to be true many times already.  

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Again, it isn't true. Good printers on nice coated stock cannot easily cover sRGB color space. They may and often do have a larger gamut volume.

“There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.” 

-Søren Kierkegaard

[NB, colourmanagement net]

You've a lot to read here about gamut warning,

But, as an aside I wanted to ask how you are calibrating the screen? IF the screen is showing colour inaccurately then even a nicely set up well profiled printer on decent media likely isn't going to match .

Of course you're going to need an accurate printer profile, I test with this Adobe RGB image

And I use this for confirmation of appearance. Some accurate reference is, I feel, a prerequisite to accurate working practices.

I hope this helps
neil barstow, colourmanagement net :: adobe forum volunteer:: co-author: 'getting colour right'
google me "neil barstow colourmanagement" for lots of free articles on colour management