Scribusoid

Author Topic: Self Printing Worflow & Color profiles  (Read 2334 times)

Nermander

  • Hero Member
  • *****
  • Posts: 1205
  • Karma: 15
Re: Self Printing Worflow & Color profiles
« Reply #15 on: December 28, 2017, 04:14:25 pm »
I have been thinking of writing a "CM for dummies" article for the wiki, but have never had time.

But the key points are:

1.
Pixels in a digital image neve have a color, they have a value/number.

Which color that value is supposed to represent is defined by the used colorspace. The colorspace is a translation from a binary value (RGB or CMYK) into a more complex color representation (like CIELab).

So as long as you are only working with the image, it is just a matter of colorspace.

This is valid for both pixels in bitmap images as well as colors defined in Scribus.

But as soon as you are going to display the color in some way, things become more complicated.

2.
A color profile hand tells "how is this (e.g. CIELab) color represented on this device?".

For a scanner a color profile tells "To what RGB value will this (e.g. CIELab) color translate?".

For a printer a color profile means "What CMYK values are needed to represent this (e.g. CIELab) CIELab color with this printer on this paper?".

3.
Now, the catch here is that every single color in the (e.g. CEILab) colorspace cannot be represented on every printer and paper combination. The CIELab can be considered to be absed on what the eye can see, not what the inks can created. And RGB or CMYK colorspaces are even narrower.

See the images on this page
https://en.wikipedia.org/wiki/Color_space

And that is where the "rendering intent" comes to play. It tells the software "what to do with colors that cannot be translated".

https://en.wikipedia.org/wiki/Color_management#Color_transformation


And the reason for not using colorspaces like CIELab in the digital images is of course space. Images would become a lot bigger if we used CIELab or something like that for each pixel.

GarryP

  • Hero Member
  • *****
  • Posts: 1600
  • Karma: 25
  • Scribus User
Re: Self Printing Worflow & Color profiles
« Reply #16 on: December 28, 2017, 04:37:08 pm »
I would imagine that the article could be long and complicated but it doesn't need to be very detailed at the beginning.

It could start with a disclaimer such as: "This process has been verified with the equipment stated at the bottom of the article but might not work in every situation. Always check with your print shop first."
Then it could have a short glossary, like you have given, with links to further reading.
After those it could be a list of: Do this; then check this; then do that; then switch this on; etc. A bit like a check-list.

Once the article is finished, people could add to it giving some extra information and notes about different circumstances and kit.
I don't think many people want to learn about this sort of stuff. Mostly they just want to know what to do so they can get on with the document itself and not worry about the technical details.
I realise that the details are very important but if someone can just do what a check-list says - maybe with a few changes - they are more likely to try it rather than just thinking that it's all too complicated and give up.
As long as the disclaimer is written clearly enough then people can at least decide if they want to try it.

The important thing is that it would need an expert such as yourself to start the whole thing rolling. Anyone could probably cobble something together but it needs the experience of someone who really knows what they're doing to make sure people are pointed in the right direction from the start.

Nermander

  • Hero Member
  • *****
  • Posts: 1205
  • Karma: 15
Re: Self Printing Worflow & Color profiles
« Reply #17 on: December 28, 2017, 08:40:30 pm »
Well, there are two major points necessary for a working color managed workflow:
- You need a profile for your monitor and ambient light conditions
- You need a profile for your printer and paper combination

Otherwise color management will give you more problems than help.

And to most people, those issues are a big obstacle.

Especially since a printer profile should preferably be updated each time you change toner/ink or paper type. And also because most people are not working in i "nautral gray" room, so colors in the room affect how colors look in screen (you most likely have seen the "Is the dress gold or blue?" thing).

Sure, some may say " I doon't need perfect color management, just good enough".

But you already get that if you stick to sRGB, which you can use without messing with profiling your things.

GarryP

  • Hero Member
  • *****
  • Posts: 1600
  • Karma: 25
  • Scribus User
Re: Self Printing Worflow & Color profiles
« Reply #18 on: December 30, 2017, 12:00:13 pm »
From what I've read about colour management - before I got confused - people seem to have three choices:
A. Set-up their workspace (including lighting and clothing) so there's no stray colour reflections; Buy a very good monitor; Buy the necessary hardware and/or software to properly calibrate the monitor; Do the calibration precisely; Find the exact colour profile for the printer/ink/paper combination they'll be using at any time; and probably a few other things too.
B. Play around with a few settings here and there and hope for the best (probably making a real mess of things).
C. Switch colour management off and have a good relationship with a good print shop.

I was hoping that it might be possible for someone to write down a list of things that worked with a particular set-up - as a general guide to start with - but, from what I understand from what you've said, that doesn't seem like it will be very useful. It would have been nice to have an article to point people towards as a starting point but if that's not practical then that's just how it is.

Since colour management is a big "selling point" of Scribus it would be good if the documentation for using it was better but that depends on someone writing it and, I'm guessing, the vast majority of Scribus users don't use it so there aren't very many people who could write something.

Would there be print shops that have someone who could advise and maybe even come out to a workplace to do the necessary calibrations? If so, maybe an article listing good print shops in each territory could be started (if there's not one already).

Nermander

  • Hero Member
  • *****
  • Posts: 1205
  • Karma: 15
Re: Self Printing Worflow & Color profiles
« Reply #19 on: December 31, 2017, 02:28:49 pm »
Color management is complicated.

People who know color management will most likely have no problems at all getting it to work in Scribus, Photoshop, Indesign or any other application with color management support.

The problem is all these people who think color management is some kind of magic that will make everything perfect. They want to turn it on because they think their color will look better, but since this is a misunderstanding they always turn out disappointed and asking "Why does Scribus make it so difficult?".

But the truth is the settings in Scribus are similar to the settings in any application supporting color management. If you just understand what they are for, you will have no problem getting them right.

I spent many evenings years ago to try to learn color management. I got so far as to realise that there is no easy way to get color management working. I was looking into creating a "poor mans solution to decent colors", but soon realised that that solution is just "Forget about color management".

GarryP

  • Hero Member
  • *****
  • Posts: 1600
  • Karma: 25
  • Scribus User
Re: Self Printing Worflow & Color profiles
« Reply #20 on: January 01, 2018, 11:09:14 am »
It sounds like people have just two practical options for colour management:
1. Put in the time and effort to learn and properly use it, or;
2. Forget about it.
I think most people will choose the latter.

This brings me on to some further questions. The first is: "If someone has gone to the trouble of getting colour management properly set-up, how often would they switch it off?" I ask this as there is a button on the bottom toolbar - next to the Preview Mode button - that lets people switch colour management on and off. Having this button where it is might suggest that switching colour management on and off was something that would be done as often as going into and out of Preview Mode. I don't think this will be the case but I'm curious to know if I'm right.

For people who don't have colour management properly set-up, having this button where it is might suggest to some that switching it on - without knowing about calibration etc. - is just a simple button click. I would suggest that this could lead to some potentially expensive problems if someone assumes that "colour is being managed" (whatever they think that means) and they try and get stuff professionally printed and it comes out wrong. I don't think that is good for the reputation of Scribus. Anyone can "just switch colour management on" by pressing the button without knowing what they're doing and think that something good will come of it when it probably won't. This is a button that causes major things to happen in the background that most users won't be aware of until they try and get something printed, and only then the problem will come to light.

So my next question is: "Does the colour management switch need to be on the toolbar?" Since:
* most people won't be using colour management, and;
* it can be dangerous for people who don't know what they're doing to switch it on, and;
* (assuming that) once someone has properly calibrated everything, they don't usually switch it off.
Should that button be where it is?

I realise that:
* Scribus is being touted as an application for professionals, and;
* there are arguments that the interface should give all users the same experience, and;
* there will be arguments such as "Hardly anyone uses render frames but that button is as prominent as the text frame button and you're not complaining about that";
* and there are many other comebacks to what I've just said.
All I'm asking is: "Should there really be a button so prominently displayed on the UI that can cause major problems for people who don't know what it does?"

I really don't want to get into any of the old discussions about what should and should not be in the UI. For me personally, I don't care, I just don't press it. I'm just wondering if there is a good reason why something so potentially dangerous should be there - looking so "innocent" and innocuous - for people to abuse without knowing that they'll probably be causing a problem at a stage when it's impossible to fix, e.g. when they get something printed and it all looks wrong.

Or, to put all of that another way: "Could the colour management switch button be removed from the toolbar without much extra hassle to most users?"

utnik

  • Hero Member
  • *****
  • Posts: 1217
  • Karma: 14
Re: Self Printing Worflow & Color profiles
« Reply #21 on: January 01, 2018, 01:49:08 pm »
hi garry

It sounds like people have just two practical options for colour management:
1. Put in the time and effort to learn and properly use it, or;
2. Forget about it.
I think most people will choose the latter.

you are working hard to discourage people from using cm!

i work on a 'poor mans cm system' – as long as i don't print myself….
my screen is calibrated under the use of a professinally printed color test chart, but just by eyeball.
the workspace is far away from any window.
as my office printer isn't a high quality  product, there's no use to try any cm on it.

Quote
…If someone has gone to the trouble of getting colour management properly set-up, how often would they switch it off?

as you can't uncheck the option to simulate printer colors on the screen in the 'new document' window, it's faster to switch cm off when creating something 'not really color sensible' in rgb than going to 'document setup' to disable the simulation, and while creating something intendet for screen use as well as for offset printing, i may switch cm on and off a couple of times while working.

Quote
For people who don't have colour management properly set-up, having this button where it is might suggest to some that switching it on - without knowing about calibration etc. - is just a simple button click. I would suggest that this could lead to some potentially expensive problems if someone assumes that "colour is being managed" (whatever they think that means) and they try and get stuff professionally printed and it comes out wrong.

in most cases this shouldn't be worse than without cm – but not better either…

Quote
I don't think that is good for the reputation of Scribus. Anyone can "just switch colour management on" by pressing the button without knowing what they're doing and think that something good will come of it when it probably won't.

here i agree. it would be good to have a good introduction for the cm (and maybe a better tooltip for this switch…)

Quote
This is a button that causes major things to happen in the background that most users won't be aware of until they try and get something printed, and only then the problem will come to light.

well, this is not a problem of a cm switch – ist's the problem of a consumer habit. ('i don't need to know cm – schribus will care about…')

Quote
Should that button be where it is?

as long as there is no other fast option, (no menu entry and no way for a keyboard shortcut) i would keep it there.

Quote
I'm just wondering if there is a good reason why something so potentially dangerous should be there…

it might be less dangerous than you think…

utnik

GarryP

  • Hero Member
  • *****
  • Posts: 1600
  • Karma: 25
  • Scribus User
Re: Self Printing Worflow & Color profiles
« Reply #22 on: January 01, 2018, 03:49:43 pm »
I'm not really trying to discourage anyone from using CM, it's just that people need to be more aware of what they need to do to use it properly rather than just switching it on and hoping for the best. I think it would be great if it was so easy to use that everyone could use it but, as has already been said, that doesn't look possible. And that's not the fault of Scribus, it's just how it is.

My main worry is that it is way too easy for people to switch it on without any calibration or configuration. Having stuff "managed" sounds better than "unmanaged" so if people see a "manage my colours" button they will be tempted to switch it on without understanding what's happening.

From what's been said it does sound like CM should be easily switched on/off when needed but I still don't think people should be able to switch it on without any configuration.

So, how about this compromise:
* The CM toggle button is kept where it is;
* but Scribus doesn't have any default CM settings;
* and CM can only be switched on when the user has given their CM configuration choices in Preferences.

Doing it this way will allow expert users to have their CM preferences and switch it off and on at will as they do now. At the same time, people who haven't been through the process of learning about and configuring CM will not be able to switch it on. They can, of course, just use "random" settings if they wish to but that's up to them. You can't always stop people making bad choices.

In this scenario, the CM section of Preferences would need to be slightly re-arranged so that the "Activate Colour Management" check-box can only be checked when the user has given all the necessary preferences, rather than the current process where it can be switched on with some defaults already selected. Scribus can still, of course, suggest some defaults but they should not be selected without user interaction; the user should have to specifically select them.

Expert users (or, people who need CM) are not hampered in any way and Scribus works pretty much exactly the same but novices (or, people who don't really know what CM is) are more protected from using something they need to learn more about before they use it. That doesn't sound too bad to me.

Is that a better way of doing things?

Nermander

  • Hero Member
  • *****
  • Posts: 1205
  • Karma: 15
Re: Self Printing Worflow & Color profiles
« Reply #23 on: January 01, 2018, 05:16:17 pm »
One of the major issues I stumbled across when trying to learn CM was: How can I verify that it is working?

And my conclusion more or less was: You can't. You have to trust it.

There is no "test image" you can view or print to verify that it is working as intended (at least not without using expensive tools to measure the colors).