Why do images look different on different papers?

[Simon Garrett]

A monitor profile is created so that you can be reasonably sure that what you see displayed on the screen is as accurate as possible in terms of color and luminosity with respect to the image file whether the color space is sRGB, AdobeRGB, ProPhotoRGB, etc. The monitor profile is not used to print.

A print profile needs to be created specific to the printer being used and the specific paper, to ensure what is in the image file is accurately processed by the printer. Lots of paper manufacturers offer printer profiles for their paper and many of the popular printers. If you have a proper matching profile then you may not necessarily need to create one for yourself.       

Yes, I agree - with a proviso.  There is a choice to be made of the white point to which one calibrates one's monitor.  Common choices are anything between D50 or 5,000K and D65 or 6,500K.  If the use of the monitor is for preparation of images for online use, then 6500K or D65 are likely choices.  But if the use is for preparing images for printing, then in some circumstances 5000K or D50 might be a better, depending on the light used to view the prints (and possibly the paper, though I'm not sure about that). 

[digitaldog]

It sometimes seems that some folk are more interested in technology than photography.

This topic has  nothing to do with photography and everything to do with color management and calibration of a display (at least the part of the discussion hijacked from the OP by Slobodan)

Why would anyone want to "profile" their monitor "for different papers" using a ColorMunki?

http://www.luminous-landscape.com/tutorials/why_are_my_prints_too_dark.shtml

The whole purpose of using a Color Munki is to ensure as far as possible (and the absolute is impossible) that the printer prints what you see on your monitor.

Exactly and that's why one calibrates a display for those papers and the reason D Fosse wrote what he did that some missed.

We do not profile our monitors for different papers

You mean you don't. Despite the capabilities found in high end reference display systems that have been available for decades.

[digitaldog]

There is a choice to be made of the white point to which one calibrates one's monitor.  Common choices are anything between D50 or 5,000K and D65 or 6,500K.  If the use of the monitor is for preparation of images for online use, then 6500K or D65 are likely choices.  But if the use is for preparing images for printing, then in some circumstances 5000K or D50 might be a better, depending on the light used to view the prints (and possibly the paper, though I'm not sure about that).  

Or none of the values you propose above since the paper and viewing conditions of the paper and print next to the display we hope to match is never defined in such discussions.
One of the biggest disservice one can provide in aiding others in this topic, one we see all the time, is a recommendation for calibration targets without having a clue about the way the print will be viewed next to the display we hope to see a visual match. Solux? GTI booth, something else? What's the luminosity of the illuminant striking the print? Don't know yet suggest the silly "always use D50" (or 5000K, they are not the same), "120cd/m2"  we hear with no recommendation on contrast ratio since so few users have control over that. Does anyone here think a matt print with a 150:1 contrast ratio will produce the same acceptable color match to the display as a glossy print with a 300:1 ratio? As D Fosse can tell you, those of us who have both the control over this and other calibration attributes can account for such differences and produce a very close match, display to print.

Kind of shocking in 2015, in a color management forum like LuLa this would be a surprise, at least to the usual suspects who hang out here. Almost as shocking as the photographer who posts (and I see this all the time): I have $800 in the budget for a display, what should I buy? (and lately it also has to be 4K as if this is at all useful in producing a visual match to a print). Substitute a lens or a camera body or a piece of software for the word display above and it's usually a different story.

[pcgpcg]

As a newbie who dove into color management by reading Martin evening's LR text and Schewe's "Digital Print" (both excellent books from which I learned much), I somehow came away with the impression that I could:
1)  buy a ColorMunki and calibrate my display properly... once
2) install icc profiles for all my papers
3) expect LR softproofing to show me something close to what my print would look like on individual papers, and allow me to make adjustments to get the appearance fairly close to what I wanted.

My what a rude awakening I have had. I accept that there is no way the white on a warm paper will look like the white on a cool paper, but I thought LR soft-proofing would at least show me that. After spending countless hours and wasting $$ of paper making adjustments for each print (for which LR soft-proofing was almost no help), posting questions here on LuLa, and lying awake deep into the night, I have realized that one must..

make a monitor profile individually for each single paper

I think this would be a great topic for someone to write up a how-to essay for Lula. Before someone tells me that it's already been stated and if I knew how to read I would know the answer, please realize that not everyone is as intelligent, perceptive, and quick to catch on as some of the experts on this site. I, for one, would appreciate a clear and thorough explanation (bonus points if presented in a non-condescending manner) for the thought process and procedures one goes through when calibrating a monitor for individual papers.  Any takers?

[digitaldog]

As a newbie who dove into color management by reading Martin evening's LR text and Schewe's "Digital Print" (both excellent books from which I learned much), I somehow came away with the impression that I could:
1)  buy a ColorMunki and calibrate my display properly... once

Calibrate to what end purpose? For many here, it's to produce a calibration and profile that results in a match between screen and print. If you use one paper, you'll end up futzing around to get that goal and you are done. But what about differing papers? We should know the answer to that!

3) expect LR softproofing to show me something close to what my print would look like on individual papers, and allow me to make adjustments to get the appearance fairly close to what I wanted.

The printer profile only knows about the printer. It knows nothing about your display or how you view the print (it assumes D50).

I think this would be a great topic for someone to write up a how-to essay for Lula.

Sorry, been there, done that.
Here's a bit of text from the SpectraView manual that may help with respect to why they do what they do.

Multiple Calibration Sets - Different display monitor calibrations can be instantly loaded allowing quick and easy switching between different calibration settings without the need to re-calibrate the display. Each time a calibration set is loaded, the necessary monitor settings and ICC/ColorSync profiles are automatically updated.

Question 4: I’m trying to match my display to my prints in order to soft proof, however after calibrating using a standard Target white point such as D65 or D50, the screen still appears too pink/magenta/green compared to the print. What can I do to make them match?
Answer: Depending on many factors such as the lighting conditions used to view the prints, paper type, and the printer profiles used for the soft proofing, the display white point may not visually match that of the paper. It is important to remember that the preset white points such as D65 are not magic numbers that must be used regardless. The calibration Target white point can be adjusted as necessary in this scenario. This is especially true if a standard viewing environment such as a light box is not being used to view the prints.
Adjusting the white point using a Kelvin or Daylight value alone is adjusting the white point along the fixed Black Body curve as viewed on a CIE xy diagram, and can vary the white point from cool to warm.
However, the color cast between the print and display may be at right angles to this curve, so in this case no Kelvin value will be able to fully compensate. A white point that lies off the standard Black Body curve can be entered by specifying it in terms of CIE xy instead of as a Kelvin or Daylight value.
To get an idea of how CIE xy values relate to the actual White Point color, try zooming in on the Color Gamut diagram on the Information window. In the example below, the Black Body curve is shown. If for example the display appears to be too green, then the white point should be moved slightly towards the lower right - this corresponds to increasing the CIE x value, and decreasing the y value slightly. Modify the Target White Point values by making small adjustment (for example increments of +/-0.003) and recalibrate the display. Several iterations may be required to find the best values. In addition to this method, the Visual Match tool described in the previous answer can be used to interactively find a visual match between the print and display.

[D Fosse]

Think of it this way: In a print, white is just the absence of ink. There's no way a profile can account for that.

Black is maximum ink - all the paper can hold. It's not true black, and it's not determined by the profile either. It's just as much as the paper can take.

These are your absolute end points. This is what color management will have to work within.

Calibrating a display is setting the stage for the profile. There's no profile yet, but you're defining the environment. You're defining what pure white 255/255/255 will look like, and what pure black 0/0/0 will look like. Screen white isn't really white, and black not really black -  except as context.

Now - and this is the tricky part, where you have to trust your eyes: You want the two to match. IOW, you want screen white to equal paper white, and screen black to equal paper black. Obviously this is a moving target where no fixed values can be given - you just need to experiment until you get a visual match. And moreover, they will vary with different papers. One paper is warm, another cool. One high Dmax, another lower.

Ergo - different calibration targets.

With all this set, icc profiles, soft proofing and all the rest can do its thing. White remaps to white; black to black. And the intermediate per channel values are distributed according to the profile.

That's the best I can do...

[JRSmit]

Digitaldog do you also per paper setting on your nec monitor also adjust black point to match the the paper contrast?

[tho_mas]

I, for one, would appreciate a clear and thorough explanation (bonus points if presented in a non-condescending manner) for the thought process and procedures one goes through when calibrating a monitor for individual papers.

... depends a bit on the hardware (monitor & measurment device) and software (calibration software and also image editing software).
The most critical part in all that is "paper white" IMHO. First: your perception of "paper white" depends on the viewing conditions... so the "ambient" light you are using to compare your monitor and your print is critical. This is why viewing boothes are useful (and of course ideally the entire room you are working in should be suited to do color critical work...). If you don't have contolled lighting for image editing/softproofing you should try to create an environment that comes as close as possible to said ideal. And the "ambient"-light should be fairly reproduceable.
Secondly: measurement devices "see" paper white" different than we humans do. Worst case is papers containing optical brighteners measured without UV-cut filter... in this case the measured "white" is actually "blue" (and since it's blue it's also much too dark as a reference).
To overcome non-ideal viewing conditions and "wrong" white points in paper profiles you can softproof without "paper-white" simulation enabled:
1- calibrate your display to match your preferred paper (both whitepoint and luminance) visually. Depending on your monitor & calibration software you can adjust the luminance and white point manually within the software ... otherwise you can use the luminance setting and the RGB-Gain of your display.
2- it's very hard to adjust the white point visually with pure white. Use a print of your prefered paper containing white and different grey patches...
3- softproof settings in Photoshop: set Photoshop's background to white. Softproof dialogue: Rendering Intend: perceptual or rel. colormetric. For the preview disable "paper white simulation" (since your monitor already matches the white point and luminance of your paper the simulation of paper white is not needed anymore). But enable "black ink" simulation so that the actual contrast range of the paper is taken into account.
This approach is not ideal either. But it takes out misleading white points in paper profiles out of the equation.

[EricV]

Think of it this way: In a print, white is just the absence of ink. There's no way a profile can account for that.

Black is maximum ink - all the paper can hold. It's not true black, and it's not determined by the profile either. It's just as much as the paper can take.

These are your absolute end points. This is what color management will have to work within.

Calibrating a display is setting the stage for the profile. There's no profile yet, but you're defining the environment. You're defining what pure white 255/255/255 will look like, and what pure black 0/0/0 will look like. Screen white isn't really white, and black not really black -  except as context.

Now - and this is the tricky part, where you have to trust your eyes: You want the two to match. IOW, you want screen white to equal paper white, and screen black to equal paper black. Obviously this is a moving target where no fixed values can be given - you just need to experiment until you get a visual match. And moreover, they will vary with different papers. One paper is warm, another cool. One high Dmax, another lower.

Ergo - different calibration targets.

With all this set, icc profiles, soft proofing and all the rest can do its thing. White remaps to white; black to black. And the intermediate per channel values are distributed according to the profile.

That's the best I can do...

Thank you -- this is the clearest simple explanation I have heard yet in this entire discussion.  However, where does soft proofing come into this picture?  I thought the soft proof was the link which let the display show you more closely what the print will look like, taking into account paper white and black points.  If this is wrong, what does the soft proof actually do?

[digitaldog]

Digitaldog do you also per paper setting on your nec monitor also adjust black point to match the the paper contrast?

Yes.

[digitaldog]

Thank you -- this is the clearest simple explanation I have heard yet in this entire discussion.  However, where does soft proofing come into this picture?  I thought the soft proof was the link which let the display show you more closely what the print will look like, taking into account paper white and black points.  If this is wrong, what does the soft proof actually do?

You invoke the soft proof, THEN calibrate the display to match that.

[pcgpcg]

Here's a bit of text from the SpectraView manual that may help with respect to why they do what they do…

Think of it this way: In a print, white is just the absence of ink...
Black is maximum ink - all the paper can hold...
Calibrating a display is setting the stage for the profile... You're defining what pure white 255/255/255 will look like, and what pure black 0/0/0 will look like...
...you want screen white to equal paper white, and screen black to equal paper black... you just need to experiment until you get a visual match... they will vary with different papers... Ergo - different calibration targets.
With all this set, icc profiles, soft proofing and all the rest can do its thing. White remaps to white; black to black. And the intermediate per channel values are distributed according to the profile.

...The most critical part in all that is "paper white" IMHO. First: your perception of "paper white" depends on the viewing conditions... so the "ambient" light you are using to compare your monitor and your print is critical... the "ambient"-light should be fairly reproduceable.
Secondly: measurement devices "see" paper white" different than we humans do. Worst case is papers containing optical brighteners measured without UV-cut filter...To overcome non-ideal viewing conditions and "wrong" white points in paper profiles you can softproof without "paper-white" simulation enabled:
1- calibrate your display to match your preferred paper (both whitepoint and luminance) visually. Depending on your monitor & calibration software you can adjust the luminance and white point manually within the software ... otherwise you can use the luminance setting and the RGB-Gain of your display.
2- it's very hard to adjust the white point visually with pure white. Use a print of your prefered paper containing white and different grey patches...
3- softproof settings in Photoshop: set Photoshop's background to white. Softproof dialogue: Rendering Intend: perceptual or rel. colormetric. For the preview disable "paper white simulation" (since your monitor already matches the white point and luminance of your paper the simulation of paper white is not needed anymore). But enable "black ink" simulation so that the actual contrast range of the paper is taken into account.
This approach is not ideal either. But it takes out misleading white points in paper profiles out of the equation.

Thank you!

[D Fosse]

where does soft proofing come into this picture?

The way I would like to phrase this, is that soft proof isn't concerned with black and white points. It doesn't have to. You've already dealt with that in setting the calibration targets, it's already covered. Assuming you use the same paper, that part of it is on permanent soft proof. But you need to change it with a different paper.

Soft proof deals with the other two dimensions in the color space, the chroma components (it may be useful to think in terms of Lab). Of course these are linked in the sense that the calibrated white point also defines neutral. D65 white also means that neutral values all the way down to black are pinned to D65. But again that's a way to define the environment that color management works in.

I don't have a lot of theoretical background in this, nowhere near what Andrew has, and the actual workings may be very different. But this is a way to look at it that I find useful.

[pcgpcg]

You invoke the soft proof, THEN calibrate the display to match that.

I'm confused. As soon as you change the calibration of the display, you've changed the appearance of the soft proof. Do you mean that you invoke the soft proof, and then change the calibration of the display until the appearance of the soft proof matches the paper print?

[digitaldog]

I'm confused. As soon as you change the calibration of the display, you've changed the appearance of the soft proof. Do you mean that you invoke the soft proof, and then change the calibration of the display until the appearance of the soft proof matches the paper print?

Yes, the calibration of the display is based on producing a match to the soft proof.
The soft proof is supposed to be such that when you view it instead of the working space, it appears to match the print. So the calibration is based on this preview (soft proof).

[tho_mas]

Yes, the calibration of the display is based on producing a match to the soft proof.

still begs the question if you are refering to softproof with or without "paper white simulation" enabled.
While the approach with "paper white simulation" enabled is of course perfectly fine it requires really good (accurate) white points in the paper profiles you are using to softroof/print. Unfortunately somtimes such profiles are not available.
If you disable "paper white simulation" in the softproof settings (but enable "black ink" simulation) then you just as well calibrate your display to visually match paper white (and its contrast range) ... but you can be sure that there is no measurement "error" that distorts the calibration.
Either way... a visual match per paper is the key...

[digitaldog]

still begs the question if you are refering to softproof with or without "paper white simulation" enabled.

I'm doing it enabled. I'm not certain it would make much difference either way, I have to think about that. The net result is a match.

If you disable "paper white simulation" in the softproof settings (but enable "black ink" simulation) then you just as well calibrate your display to visually match paper white (and its contrast range) ... but you can be sure that there is no measurement "error" that distorts the calibration.
Either way... a visual match per paper is the key...

The advantage with soft proof simulation (with good profiles) is that while you'll still get a visual match either way, the WP adjustment from the display calibration is not as 'strong' or 'intense' so when soft proof isn't on, you don't have to see that effect. The advantage without using simulation is you're doing all the heavy lifting with the display profile. I suppose the capabilities of the calibration software needs to be examined too. SpectraView has something like 3 different methods of adjusting WB and can do so to a very precise degree numerically or visually. The same could be said for black. You can control the contrast ratio in the display or with the profile (or perhaps a bit of both).

Let's say we need a very warm color appearance to match display and paper. We'd see this warmth with or without soft proof if we build this into the display calibration and it would be invoked all the time. If we let the profile do most of the output simulation, with soft proof off, we wouldn't see this warmth. Only when paper simulation is on would the warmth would kick in more strongly than without. Again, we agree that the net result is a match. Using the paper profile as much as possible would take most of the burden off the display calibration which wouldn't be as visible if you're doing work without considering the final output (soft proof) while doing most of the editing. In that mode, the display is more output agnostic and with the soft proof on, it's more output specific.

[pcgpcg]

In Lightroom, what is the point of soft-proofing with "Simulate Paper and Ink" unchecked? With this unchecked, I see no change in appearance of an image when I click on "Soft-Proof", regardless of which paper profile is selected.

[tho_mas]

I'm doing it enabled. I'm not certain it would make much difference either way, I have to think about that.

both ways must lead to the same final outcome (in theory as well as in practice).

The advantage with soft proof simulation (with good profiles) is that while you'll still get a visual match either way, the WP adjustment from the display calibration is not as 'strong' or 'intense' so when soft proof isn't on, you don't have to see that effect.

I think it depends on the papers and the respective profiles. With really "good" profiles I would most likely also think about enableing "paper white simulation" as a reference for my monitor calibration.
But personally I am mostly printing in a lab on photo-papers. These do of course contain lots of optical brightners. The guys running the lab make really good profiles (as good as it gets with analogue photo papers and the chemical process). Though they experimented a while with UV-cut filter they came to the conclusion to stay with the conventional way of profiling (so without UV-cut). While the UV-cut filter provided much better (="real world") white points for softproofing the saturation of the actual prints never came as close as with the profiles created without UV-cut. The UV-cut prints somehow looked "lifeless". For whatever reason.
I've also seen quite some vendor profiles for inkjet prints that showed green or magenta cast. "Paper white simulation" with such profiles is a pretty fruitless venture. This is why I think the main advantage of softproofing without "paper white simulation" is it makes you pretty immune against "bad" profiles (and it takes out one unknown variable out of the process).

[tho_mas]

In Lightroom, what is the point of soft-proofing with "Simulate Paper and Ink" unchecked? With this unchecked, I see no change in appearance of an image when I click on "Soft-Proof", regardless of which paper profile is selected.

In LR you can't seperate "paper white simulation" from "black ink simulation" (at least not in LR4... which is the latest version I am familar with). So either you turn on "softproof" (wich enables both "paper white" and "black ink" simulation... since this is the "academical" correct way... so the way softproofing should work in theory).
So when unchecked in LR you are only previewing a relative colormetric color space conversion to your printer profile (and since you see no change in the appearance of your image it either fits within the gamut of the printer... or both the image and the printer profile fit within the gamut of your monitor profile).