A Whole New World

When I started exploring how to print the paintings I’d been working on in Rebelle, I thought it would be a fairly simple endeavor. After all, printing is a mature and developed technology, surely it was as simple as just finding a printer with the technical capabilities of printing high resolution smooth gradients on good papers with durable inks, right?

…Nope.

Turns out I’d entered a world that is a deep and complicated specialty, and I quickly felt that I would need another degree to even begin to understand it. I spent months wading through color and light frequency diagrams, puzzling over ICC/ICM profiles, talking to experts who tried to explain agreed upon absolute color definitions and how relative color converts in and out of it.

To be honest, I’m still confused! But I did end up figuring some stuff out and how to apply it to my needs as a digital artist: How to get what I’m looking at on my screen to be very close to what comes out of my printer.

And that’s what I’d like to share.

Because all of the articles I read and experts I talked to skipped over some very important basics that would have let me do what I needed very quickly instead of spending months trying to learn all the theory that, to be honest, I don’t really care about right now.

Tl;Dr

• Everything sees and reproduces color differently, which makes accurate color reproduction a very complex thing.
• To solve this problem, people have agreed upon some absolute color models.
• These absolute color models aren’t practical to use in everyday situations for some reason, so more practical ‘color spaces’ have been developed for that.
• ICC/ICM profiles are composed of information on how specific viewing situations like monitors, ink and paper reproduce color, and instructions on how to convert these colors into and out of absolute models and color spaces.
• So, you need several pieces all slotted into the correct places to correctly reproduce color. Unfortunately ALL of these pieces are called ICC/ICM profiles, even though they go different places in a color management workflow and do different things. There are 3 main types: Color Space, Display and printer/paper/ink profiles.

Simplified Theory

There’s TONS of stuff out there if you want to learn more about color management theory. I still don’t understand most of it, but that’s not the point of this article anyways. Here’s the basics I needed to know to get the prints I wanted to get.

Absolute Models

I don’t know much at all about the absolute color models. There’s one called Lab and another called XYZ that are the most common ones used. I’m not sure how important it is to try and use the same one across profiles.

These models are used as absolute references so we can convert different viewing situations into something that looks very similar across all of them.

Color Space

These are your working spaces. They describe the range of colors available to you. Unless you are doing color separation printing, where CMYK are all printed as different layers, you will use RGB color space for everything, including CMYK inkjet printers like the one I use.

The 3 most common RGB color spaces are:

• sRGB IEC 61966-2.1- a color space that can be displayed on all screens. Use this if your work will always be digital.
• Adobe RGB (1998) – A broader color space than sRGB. Use this if you are going to be printing anything, so you can convert the colors closer to what the printer will output.
• ProPhoto RGB – a much larger color space that contains more colors than the other 2, especially within the darker areas. Allows a photographer to take a picture of a dark area and then lighten it up later with less distortion. I don’t use this one, so don’t know much more about it.

Screens

Each screen displays color in a different way. To view accurate color on them, screens must both be calibrated to display accurate color, and an ICC profile made to describe to the color management process how they display color.

Some higher end monitors come with a ICC profile from the manufacturer, and that’s great. But apparently as screens are used and things ‘break in’ the color can change over time. So if color management is vital to your project. then it’s best to calibrate and create new profiles every few months.

A screen ICC profile is used in the operating system’s display settings, to tell the OS how to display colors on the screen. Many graphics programs will reference this so they know how to display colors within the program.

There’s plenty of stuff on the internet about how to add and activate display profiles on various operating systems. Look up one for yours!

Prints

Each printer/ink/paper combination reproduces color in a different way. So it’s important to have a dedicated ICC profile for each combination.

My art printer came with icc profiles for the manufacturer’s paper. If you search, you can probably find profiles that people have made for other combinations. The paper manufacturer that I’ve bought from has made ICC profiles for all of their paper for various printer models, including mine, which is incredibly useful.

Apparently it’s more difficult to make a profile for paper than it is for a screen, but it can be possible with home tools. I believe that there are people who offer this service if you’re willing to mail them pages your printer has printed if you can’t find a profile for the combination you’re using.

This profile is used in 2 places: within the printing color management workflow, to tell the printer how to manage its ink, and within the graphic program’s ‘soft proofing’ viewing space, so you can see what it will look like and make changes before spending resources to print it.

How this works in Rebelle

Whew! So much to work through before we even get to Rebelle, but we made it! Yay!

Open the Color Management panel in Rebelle by choosing Edit/Color Management. You can also find it in Edit/Preferences/Color Management.

Default profile is referring to the default color space Rebelle will use every time you make a new project. Since I’m printing my art, I’ve chosen this to be Adobe RGB (1998).

General shows the current profile of the file you are working on, which might be different than the default profile. For instance, I might be working on something that will only be used digitally, so I’ll work in the sRGB color space instead.

Policies is self explanatory. This tells Rebelle what to do when you open or import things. I have it set to ask me what to do if the color space of a file I open is different from what the default and to convert things I import to the current color space I’m working in.

Display is one of the things I found confusing. Apparently Rebelle doesn’t look at what the OS display setting is, so you have to tell it what to use. Set this as the display profile you have set in the OS display setting.

Proof Colors is where the magic takes place. This tells Rebelle how to simulate what the printed page should look like. You need to put your printer/paper profile here.

Rendering Intent determines how the colors are converted, using different philosophies. There’s plenty online about what they all do. I’ve been told that Relative Colorimetric is a good general use setting. Perceptual can also be good if you aren’t liking how RC is converting.

Black Point Compensation still confuses me. I’ve been told to turn it on if the darker areas look blocky.

Gamut Warning is trying to show you where you have colors that are outside the range that your printer will print. I have no idea what to do at this point, but I assume the magic behind the scenes will try to convert these colors into something that it can print. Or you can try to do it manually somehow.

Soft Proofing

All right! We’ve got all the little bits and pieces explained and put where they belong. To see what your printer will put out, we need to turn on soft proofing.

Go to View/Proof Colors and click to toggle it on. This makes a big difference on my screen, since I print on matte paper. Now you can adjust things until it looks like you want!

If you’re using a printing service, ask them for their ICC profile for the media options you’ve selected so you can do soft proofing before you order prints.

Printing

Rebelle doesn’t do printing, so once you have things set the way you want, you’ll need to export a file and open it in a different program that does printing with printer ICC profiles.

The file you print with should be in Adobe RGB (1998) color space and no less than 300 dpi. If you were working in a lower resolution in Rebelle and have Pro with nanopixel, you can export a x2 or larger file and adjust the dpi in a different program to raise resolution without lowering quality. It can take a little math to calculate how the pixels are shuffled, but is very doable.

You can look up guides on how to use printer ICC profiles with the printing programs you use! The ones I use each do it differently.

A suitable free option might be Gimp, though I’ve never used it. A quick search brought up this tutorial on how to use printer profiles in it.

Converting for Digital Viewing

Since I am working primarily in Adobe RGB these days, I need to convert the images I intend to be viewed in digital environments, like the ones on this website! If I leave the images in Adobe RGB, then screens that can’t view the broader color space will show the image as less saturated.

To prevent this, I use Rebelle’s Edit/Convert to Profile… dialog to convert the image to sRGB before exporting a file meant for the web. Be sure you don’t overwrite your Adobe RGB file with this sRGB one so you don’t lose the broader color range. I usually just hit ‘undo’ once I’m done exporting.

‘Assign Profile’ is meant for images that don’t have any color working spaces applied to them. Don’t use it if an image does, this will cause odd color issues.

‘Convert to Profile’ properly refers to the absolute color model and will convert it so it looks right.

I hope this was helpful! Happy printing!