Adobe InDesign CS/CS2 Breakthroughs [Electronic resources] نسخه متنی

Color Mismanagement

Understanding Color Management Differences

I'm printing documents for clients (some use CS and some use CS2), but I'm finding huge differences in how these documents print color from when I was using CS.

You're right, Adobe made big changes in InDesign's color management system in CS2. For starters, color management is turned on by default in CS2, so pretty much everyone is using it whether they know it or not. Second, InDesign CS2's "Preserve Numbers" feature is a huge step forward because it stops CMYK colors that don't have a corresponding color profile from being converted at print time (or when you create a PDF). The result: your 100% black text won't change to four-color text when this is turned on. Hooray!

On the other hand, Adobe alsomade a change that they didn't really document or tell anyone about and it could cause major headaches. Each InDesign CS2 document can have its own document color management policies, separate from the application's own default policies. That makes it more like Photoshop. But the problem is that there is almost no way to find out what a document's conversion policies are! Oops. The only way to see a document's settings is to:

1.

Close all documents.

2.

Choose Edit > Color Settings.

3.

Next, turn on the Ask When Opening checkboxes for both Profile Mismatches and Missing Profiles. (These are off by default.)

4.

Click OK to save these new default settings.

5.

Now open the document. If the profiles or policies in the document are different than your default application settings, InDesign will now inform you (Figure 8-5).

Is this a good system? No. Is it better than before? Probably, but it's still far too confusing.

That Ain't Black Text, it's CMYK!

Every now and then, when I print or export a PDF file, all my text (which is just set to 100% black) turns to a rich black that is, it prints with cyan, magenta, and yellow, too. That sounds good, but it's a disaster on press, especially for small text that comes out looking fuzzy.

Surprisingly, this is one of the most common printing mishaps in InDesignso much so that Adobe spent a huge chunk of time adding a new feature in CS2 that attempts to eradicate it. The problem arises when you print to a different output profile than your built-in document profile. But don't feel stupid if you don't even know what a document profile is; most folks don't!

A document profile is what tells InDesign what the colors in the document look like. For example, you might specify 100-percent magenta, but there are lots of different magenta inks (some more red, some more orange). When you create a new document and color management is enabled (it is by default in CS2), InDesign assigns an RGB and a CMYK default working space profile to the file (as specified in the Edit > Color Settings dialog box). In North America, the default CMYK profile is usually "U.S. Web Coated (SWOP) v2".

If you specify any other CMYK profile when you print or create a PDF file, InDesign may convert the CMYK colors in your document to the CMYK equivalent for the output device. In other words, InDesign tries to make the magenta in your output match the magenta in your document, even if that means adding a little yellow or cyan to make it work.

InDesign CS also converts your 100-percent black text to an equivalent in the output profile's color space, which may mean adding a little cyan, magenta, or yellow to make it work. This is almost never what you want, but InDesign doesn't know that.

So, in InDesign CS the solution is to always leave the Printer Profile popup menu (in the Advanced panel of the Export Adobe PDF dialog box, or the Color Management panel of the Print dialog box) set to Document CMYKat least when printing final separations (Figure 8-6a). If you decide you need to use a profile other than the default, then use Edit > Convert to Profile or Edit > Assign Profiles to change the document profiles before printing or exporting. (While this, too, may change your colors unexpectedly, it fortunately leaves objects and text colored with the [Black] swatch alone.)

Another option is simply to turn off color management (in Edit > Color Settings) before you print or export a PDF file.

InDesign CS2 offers a new feature, called Preserve CMYK Numbers. When you choose an output profile that differs from the document profile, InDesign lets you turn on the Preserve CMYK Numbers checkbox in the Color Management panel of the Print dialog box. (When exporting a PDF, you can choose "Convert to Destination (Preserve Numbers)" from the Color Conversion popup menu in the Output panel of the Export Adobe PDF dialog box.)

When you turn on this option (Figure 8-6b), InDesign CS2 will not convert any CMYK colors to the new CMYK color space except imported images that have a profile attached to them. (Actually, unless you change the defaults, InDesign's policies ignore profiles in CMYK images, too, because Adobe assumes that if they're in CMYK mode, they're likely "press-ready." So they, too won't be changed when you turn on Preserve Numbers.)

We almost always leave this turned on, so our black text stays black no matter what profile we choose. Even better, if we specify 100-percent magenta somewhere in the document (or any other process color), it'll always print at 100-percent magenta, without any other colors muddying it up.

By the way, here are a couple other things to watch out for: Every so often we find someone who is using a black swatch based on RGB colors instead of the normal [Black] swatch in the Swatches palette (which is defined as 100-percent process black). In this case, the RGB black always becomes a four-color CMYK black when you print in CMYK (or print separations). Or, a newcomer to the graphic design field might naively use InDesign's [Registration] color (which is defined as 100-percent of each of the four process colors) instead of the normal [Black], because they look the same on screen. Tsk-tsk.

NOTE

If you're using Distiller to create your PDF files, you should note that it, too, can convert colors including converting 100-percent black to a CMYK black. Take a look at the Color settings in Distiller's Settings > Edit Adobe PDF Settings feature.

Colors Go Blah

My color images and text usually look great on screen, but sometimes all my colors suddenly appear washed out both on screen and when I print. Vibrant reds become dull rust; bold blues become, well, just blah.

There are so many things that could be going on here, but most of them boil down to one unfortunate truth: process colors (CMYK) are usually more dull when printed than RGB colors display on screen. InDesign tries to give you clues about this discrepancy, but the clues (changing colors on you) often just make people more concerned than reassured.

For example, lets say you import an RGB image and then place an empty frame anywhere on the page. If you set the Blend Mode of that empty frame to Multiply in the Transparency palette, InDesign says, "Hey! I have to simulate a transparency effect!" It looks at what setting you have chosen in the Edit > Transparency Blend Space submenu. If this is set to CMYK (it usually is), then InDesign changes the display of all the colors on the spread to a CMYK preview. The result: The colors become somewhat washed out (Figure 8-7). Again, this affects all the colors on the spread, even if that object with a transparency effect is nowhere near them.

TIP

Look at the Pages palette. If a spread has some sort of transparency on it (which will affect how it is displayed), its page icons will appear with a checkerboard effect.

If you change the Transparency Blend Space to RGB, then it'll look better on screen, but that's a mistake if you're going to print CMYK separations down the line. The only time you should use the RGB Transparency Blend Space is when your final output will be on-screen or on an inkjet printer.

Similarly, InDesign refigures its display using CMYK if you turn on View > Overprint Preview or Separations in the Separations Preview palette. All your RGB images and colors will dull.

You'll really see the effect if you turn on the View > Proof Colors feature. This tells InDesign to display what your page will look like in the final CMYK workspace. If you choose View > Proof Setup > Custom and turn on the Simulate Paper Color option, you'll be amazed at how terrible your images will appear in print (Figure 8-7). Of course, seeing a "soft proof" like this (proofing on the screen) only makes sense if you have created a custom monitor profile. (See Real World InDesign CS2 or Real World Color Management for more on that topic.)

The thing is that none of these change your actual output on a PostScript device when printing separations. They just give you varying degrees of accuracy on screen as to how the colors will appear.

Colors can also change radically when you print or export a PDF file. The key settings that control color in the Print dialog box are in the Output and Color Management panels. When exporting a PDF file, pay attention to the Advanced panel (in InDesign CS) or Output panel (in CS2).

If you're printing to an RGB device (and inkjet printers generally fall into this category even though they print with process-color inks), make sure you choose RGB from the Color popup menu in the Output panel. Then choose an appropriate destination profile from the Profile popup menu in the Color Management panel.

[View full size image]

[View full size image]

When printing separations or to a PostScript RIP, you should probably choose CMYK or Unchanged from the Color popup menu. (Note that if you're using spot colors, InDesign won't convert them even if you choose CMYK; it generally only converts spot colors to process when you turn on Simulate Overprint or tell it to separate spot colors using the Ink Manager.) Again, the choice of the proper destination profile is crucial so that InDesign knows whether and how to convert your colors.

By the way, if you really want bright, saturated colors on a color PostScript device (like a color laser printer), you should probably just choose to send it RGB colors rather than CMYK. It won't necessarily be an accurate proof of anything, but it'll be prettier.

Tip

The reason you're getting bland prints from an inkjet printer may have nothing to do with InDesign. Click the Printer button (or the Setup button, in Windows) inside InDesign's Print dialog box to see the printer driver's settings. Many printer drivers have their own color management controls which can greatly affect how color appears on the page. Try turning those off or adjusting them for better color.

Tip

When you prepare a PDF proof to send to a client, consider saving it in an Acrobat 4 format and convert all colors to CMYK or RGB, which flattens all the transparency effects and allows you to turn on the Simulate Overprint checkbox in the Advanced (in CS) or Output (in CS2) panel of the Export Adobe PDF dialog box. Otherwise, you'll have to tell them to choose Advanced > Overprint Preview in Acrobat, or in Preferences > Page Display in Reader. (In our experience, the fewer steps a client needs to perform, the better.) This PDF is not appropriate for a final print, of course just for a rough proof.

Stop Overprinting the Black Already!

I have to admit it: Sometimes I miss a feature or two from QuarkXPress. For example, there's no Trap Information palette in InDesign, so I can't specify the trapping value for a particular object. The place this trips me up the most is when I want to set some large black text to knock out instead of overprint. How can I do that in InDesign?

When you put large black text (or any other black object) over a color image, or overlapping multiple colored objects on the page, you may see those objects through the black after all, in reality black ink is not nearly as opaque as you might think. The problem, as you discovered, is that InDesign automatically sets 100-percent black objects (applied with the default [Black] swatch) to overprint and there's no "knockout this object" feature.

One solution is to turn off the "Overprint [Black] Swatch at 100%" checkbox in the Preferences dialog box. (In InDesign CS, it's in the General panel of the dialog box; in CS2, it's in the Appearance of Black panel.) Unfortunately, this makes all your black text knock out, which causes untold headaches when printing small text or thin black lines.

Instead, you might consider using a rich black: Create a new CMYK color defined as 15- or 20-percent each of cyan, magenta, and yellow, plus 100% black. A rich black not only looks blacker in print, but it always knocks out all the colors behind it.

Another solution is to create a new CMYK color swatch that is simply 100-percent black. InDesign won't automatically overprint it, even though it's functionally the same as the swatch called "[Black]." Use the regular [Black] swatch most of the time, but use your 100-percent black when you want it to knock out.

NOTE

You know that 100-percent black ink isn't totally opaque it's more charcoal colored when you print it on white paper. A rich black (black with other process colors mixed in) is actually darker than plain black ink. But almost every software application in the world displays black and rich black as the same. InDesign CS2 offers you a choice of how your black ink should look in the Appearance of Black panel of the Preferences dialog box.

The preference panel lets you control how black should appear on an RGB device, such as your screen or an inkjet printer. By default, InDesign CS2 is set to Display all Blacks as Rich Black, which means any color that is 100-percent black or darker will appear as solid black. But if you choose Display All Blacks Accurately (or Output All Blacks Accurately), then InDesign will use a dark gray for 100-percent black.

We tend to leave these set to the default. When we want an accurate picture of what colors (including black) will look like, we generally use the View > Proof Colors feature instead.

Overprinting Doesn't Add Up

I have no problem using the Overprint Fill and Overprint Stroke features in the Attributes palette to set objects to overprint spot colors. However, when I try to overprint a process color over another process color, it's flaky: Sometimes I get what I expect and sometimes I don't.

Overprinting has long been a misunderstood child. When you overprint a fill or a stroke, you're not actually saying "add this color to the background colors." You're just saying "don't knock this color out from the background." There's a subtle difference, but it has huge implications.

Where people get into trouble is in overprinting the same color. For example, let's say you have one light-green object colored 30-percent cyan and 20-percent yellow. You put it on top of a purple background that is 50-percent cyan and 80-percent magenta. If you set that green object to overprint, it seems like InDesign would add all the colors up and you'd get 80-percent cyan plus the other colors. But PostScript doesn't work that way.

In PostScript, whatever tint is on top wins. If you put 30-percent cyan on top of 50-percent cyan, you get 30-percent cyan whether you overprint it or not.

The result in the above example would be a color lighter than the background: 30-percent cyan, 80-percent magenta, and 20-percent yellow (Figure 8-8).

When you want to add colors, consider using a transparency mode instead of the Overprint features. Setting the top object to Multiply in the Transparency palette will probably get you closer to what you want. Another good option is the Color Burn mode.

To see how the overlapping colors will mix, open the Separations Preview palette (Window > Output > Separations Preview), turn on Separations (viewing all the plates) and position your cursor above the overprinting color area. You'll see what percentage of each color will be applied to the same area.