RGB workflow in ‘real life’

You might have heard about the RGB-workflow and InDesign. But what exactly is it? What can you do with it? How do you set it up? What’s the advantage? A lot of good questions and I’ll try to answer them in this article. Just keep in mind: There’s really only one strategy for graphic designers using the RGB-workflow: Retain as much information as possible.

What does ‘retaining information’ mean?

“There’s no such thing as one correct and perfect CMYK”

The idea is simple really: retain the original files within their original colorspace including their ICC-profile. Don’t use Photoshop and start converting scans or digital photo’s to CMYK. I know some of you are probably thinking: “What? The artwork needs to be CMYK because it’s going to a printer!” Instead, work with the RGB-files and always make sure you save it with the original ICC-profile. (There’s a little check box ‘embed color profile’ when you save the PSD file. Make sure it’s checked). You can alter the PSD file and just use ‘command + S’ all you want after selecting that check box. Now if you haven’t got a digital photo or scan and you need to start from scratch, keep in mind to start with a Photoshop file in the RGB modus. The standard Adobe RGB (1998) is a perfect color-space for almost all your artwork except for the Internet or TV. When you’re done working in Photoshop we’ll use InDesign to pick up this (RGB) PSD file and convert it to the correct CMYK-color-space when we’re creating the press-ready PDF.

The correct color settings

Now if we’re going to let InDesign convert the image to CMYK, we’re going to need the correct CMYK ICC-profiles. Should you decide to start using the RGB-workflow you’re gonna want to know about ICC-profiles. And if there’s one thing you need to remember it’s this: There is not such a thing as ‘the best’ or ‘correct’ CMYK-profile. (Even though Adobe InDesign act’s like there is). There’s a color profile for every sort of paper and printing-technique. An ICC-profile contains information regarding the paper and printing technique. Choose the wrong one and the colors of your artwork will get optimised for the wrong kind of paper. A newspaper uses different quality of paper than high quality printers. So you need to know about the paper. If you don’t know for sure what sort of paper the printer will use (and this happens a lot) you really need to communicate about it with your printer. (It doesn’t matter if he’s in China or whatever. You bet your ass your client is gonna hold you responsible if the end result looks like crap).

InDesign needs to know what CMYK profile to use. There are literally a thousand kinds of paper and printing techniques and for most of them you won’t be able to find a good ICC-profile. This used to be a big problem. Nowadays when I send out artwork to a printer I use one of the free, standard and high quality ECI (European Color Initiative) ISO ICC-profiles. They come in really handy. What they do basically is set an international standard a good printer can follow. Very good printers can even become color certified (ISO 12647-2). I’m not always in a position to choose my printer, but when I am, I work with ISO-certified printers. ISO 12647-2 is an international standard and it’s one of the best ways to achieve predictable colors. Using these ISO profiles you’ve got the basics pretty much covered. I refuse to use ‘special’ profiles a printer made for his printing press. Think about it: What would happen if I were to order several thousand brochures at another printer? The colors of my artwork would probably be completely different, that’s what would happen. Avoiding situations like that is why I prefere to use ‘ISO-certified’ printers.

The most important ISO standard ICC profiles are:

1. ISO Coated v2 (ECI) for high quality glossy.
2. ISO Uncoated for uncoated paper.
3. ISO Uncoated Yellowish for the highly common uncoated paper with a yellow tint.
4. ISOwebcoated.icc for standard magazine CMYK (LWC paper). Most magazines do have an ICC-profile. Ask their advertising department. If you can’t get the information you can use this standard profile and at the very least have the basics covered.
5. ISOnewspaper26v4.icc for standard newspaper CMYK. There’s also one for plain black called ISOnewspaper26v4_grey.icc you could use with Photoshop. (InDesign can’t produce correct greyscale PDF files with a profile).

You can download the ISO-profiles and detailed information from the ECI website. And, like the ECI says: “In case you are not sure which ICC profile for offset printing to use, it is recommended to use ISO Coated v2 (ECI)”. Just scroll down to ‘ICC profiles from ECI’ and make sure you download the 2008 ones.

These ICC-profiles are available just as soon as you’ve put them in the correct directory: Macintosh HD / Library / App Support / Adobe / Color / Profiles. (You do need to restart). There are a few different ways to select the profiles. If you’re using the entire Creative Suite (version 2 or higher) you can use the app called ‘Bridge’ and select the correct settings for all of the apps inside the Suite: Bridge / Edit / Creative Suite Color Settings. If you’re just using InDesign and/or Photoshop you need to change the color-settings inside both the apps: / Edit / Color Settings. You can only choose one RGB and one CMYK color-space.

And that’s too bad really. This set up forces you to select just one CMYK. You already know there’s no such thing as ‘one perfect CMYK’. Most European people don’t know about the other CMYK profiles and they select the standard “Europe ISOCoated FOGRA27”. This is really only appropriate for the smooth kind of white paper. Should you use this setting for a newspaper ad you are gonna end up with very dark results and a loss of details when they print your photo’s inside your ad. Like I said above, newspapers use uncoated and recycled grey paper that will suck up each color (Cyan, Magenta, Yellow and Black). Also very important: there is no white. Instead there’s a brown grey color exactly like the background around this site. (Yes, I designed it like that on purpose so you won’t forget. Just remember: “There is no white”).

Using the correct CMYK

So if there’s no such thing as one correct and perfect CMYK color-space why does InDesign force you to select a standard CMYK via the preferences? Changing the preferences each time for each document is tiresome and dangerous. Exept for a pop-up when you open an InDesign file, InDesign does not provide visual feedback regarding the CMYK-profile a document was set to. (Photoshop does, just check the bottom corner of a document).

Now I don’t work for Adobe but I did get a chance to ask Adobe Principal Scientist Dov Isaacs this very same question some time ago at the Adobe HQ in Amsterdam. I suggested InDesign should adopt Photohop’s way of working with profiles. Whenever a new document is created just provide the user with a possibility to specify not just the size and bleed but also the (CMYK) color space. And (like Photoshop) show the name of the profile in the top or bottom corner of the document. But the thing is, Adobe really wants us to adopt the new PDF export options and just forget about CMYK-only files all together. In tomorrow’s perfect world you need not worry about all those CMYK profiles and export an RGB PDF file including every ICC-profile of all the Photoshop and Illustrator artwork. You can even retain the InDesign layers, The JDF (or Job Definition Format) and not flatten the used transparency. The printer will take care of the optimal and correct conversion. Of course this would be a perfect workflow.

But in today’s world?

I’d love to send out a ‘smart’ PDF like that but right now I’m not going to. I need to provide the printer with a Certified PDF and those need to be CMYK (and can’t contain any images or artwork with embedded ICC-profiles, layers or transparency). So what’s the next best thing? Well, there are three ways to work with the InDesign app and another CMYK color space. First off you could select another CMYK ICC-profile in your preferences (InDesign / Edit / Color Settings). All the documents you create as of now will use the new settings. Now if you’re working in an existing document with (for example) the ISOcoated_V2 profile and you want to create a newspaper ad, you could also assign another CMYK profile just for this document. For newspaper we would need the ISOnewspaper26_v4. A little warning: meddling with profiles if you don’t know what you’re doing can be dangerous. There is a big difference between assigning a profile and converting to another profile! Had you accidentally chosen ‘Convert to profile’ your swatches would have gotten screwed up. 100 cyan would become something like C=93 / M=3 / Y=0 / K=4. Even though this is technically correct (we are converting from one CMYK color space to an other) it’s not what we’re looking for right now.

The third and easiest way to work with another CMYK color-space is to select it when exporting to PDF. Any RGB image placed in InDesign will get separated to the CMYK-profile you select at exporting. When InDesign does so, it takes in account all the information inside the ICC-profile. For instance: for newspaper the maximum ink limit is 290%. Using the ISOnewspaper profile InDesign will make sure all the RGB Photoshop artwork will separate to no more then 290%. This way the colors of your ad will look at their best when printed. Now if you’re thinking: ‘Woah! 290% ink? What does that even look like!?’ You need not worry. InDesign has a very good way of showing you: InDesign / View / Proof Set up / ISOnewspaper. Make sure you select ‘Simulate Paper Color’ and ‘Simulate Black Ink’. Now all of a sudden your ad looks like crap. But don’t worry. Newspaper really do print this grey and the paper really is this grey/brown. Knowing this you might want to alter your RGB image a bit. Up the contrast or just fiddle around a bit more… And that’s okay because Photoshop also knows this trick of simulating how your printed artwork will look when printed. (For this Photoshop uses the information inside the ICC-profile). Just open the RGB and add a few adjustment layers. Don’t go screwing around the good RGB layers. Just ad a layer or two for the newspaper and remember to name them something like ‘newspaper touch up’. This way you can keep one good RGB image for all your artwork.

Retaining information

So using this RGB workflow you retain the original RGB image. In the old days you would have separated the RGB to (the standard) CMYK and do your designing and retouching in that image. In doing so you would have optimised for only one CMYK color space and you would have wasted a lot of color-information because the RGB color space is so much larger than the CMYK color space. Suppose you needed to create one smashing visual and use it for an entire campain: A glossy brochure, a website and an ad campaign. You’ve got the standard CMYK image so the glossy brochure would print fine. Your client would be happy. But the same image in a newspaper-ad would totally suck (way too much ink and a lot less contrast) and the website colors would look like the CMYK colors instead of nice bright RGB ones. Of course you could always convert the CMYK image back to RGB but because you can only convert you basically force Photoshop to let the colors look like the CMYK colors. It would not bring back the color-richness and details so there’s no real gain. And besides; you’d end up with a set of different visuals instead of one great RGB image.

Check out these images. Number one is an sRGB image. Two is sRGB converted to ISOcoated CMYK. And three is CMYK back to sRGB. As you can see number three certainly does not look like number one. This is what happens when you convert. Of course the images are best viewed with Safari, because of the ICC-profiles. (Windows-users: There’s a Safari for you guys as well. Pick it up, it’s free).

Check out this image. The first one uses the sRGB** (or small RGB) color space a lot of cheaper camera’s (and the Internet) uses. Number two simulates what the same image looks like in CMYK. The last one is the CMYK image converted back to sRGB. As you can plainly see converting a CMYK image back to RGB does not magically make the image the same again. Color information and details have been lost. So don’t go converting back and forth between RGB, CMYK and RGB.

An other way to screw up your colors and generally piss of the print-guy

There’s one more reason to start working with RGB images. In the old days you would have converted an image to (the standard) CMYK and start retouching and editing the Photoshop file. You migh ‘up’ the contrast, brighten the colors and ‘what not’. There’s just one problem: You have already converted from RGB to CMYK! So Photoshop has already maximised the ink limit to start with. And now you’re upping it by editing the file and upping the contrast, adjusting the channels and changing the colors. Nine out of ten times you end up with way too much ink. There’s no way the printer will be able to reproduce what you see on your RGB-monitor. With too much ink the artwork will create problems for the printing press. I’ve seen artwork with up to almost 400% ink because the designer liked ‘that specific black’. Well you’re fooling yourself and you’re not gonna get it! The printer might even end up with wet prints. The large quantity of ink takes up more time to dry. It would have been much better to work inside the RGB file and make it as black as possible inside RGB. Let InDesign convert it to the maximum black when separating to the correct CMYK. And you’ve guessed it: The maximum full color black will vary for each profile. Each CMYK-profile will provide you with the maximum a specific printer can handle. You can rest assure the printer will at least be able to print what you’ve had in mind because you have already checked how your artwork will look when printed.

So now you know a little bit more about profiles and perhaps even why some of your artwork looks to ‘dark’. It’s all in the profiles. The good news is there’s a worldwide (ISO)standard and the profiles and the information they’re based up on and are absolutely free! If all of this dazzles your mind, don’t worry. Drop in on your printer. Don’t just email the guy, but take your time and get over there. Smell the ink, see the press and ask him about profiles and how to set up a good work-flow between your desk and his press. It’s not just in your best interest but also in his own.

*A –very– short explanation about ISO 12647-2: It is based upon the “FOGRA39” data-set (from the Altona Test Suite). Any printer can download the ICC-profiles, order the set and test-print it. After printing he can measure the colors and compare them to the standard data-set. He can keep printing and measuring until he achieves ‘good’ colors. ISO 12647-2 certified printers have a measured quality of color, work-flow and communication.

**I’ve used sRGB but most of the time you would use something like “Adobe RGB 1998”. The difference would be even bigger because aRGB’s color space is bigger than sRGB. Because I’ve enclosed the ICC profile in these images it would be best to view them in an ICC-aware browser like Safari, Omniweb or Firefox (if you turn it on by typing “about:config” into the address bar. Change the value of “gfx.color_management.enabled” to true and restart Firefox).