InDesign for QuarkXPress Users [Electronic resources] نسخه متنی

Transparency Must Be Flattened

When it comes time to print, the beautiful transparent effects that you've created must be sent to a machine which doesn't know what transparency is. PostScriptthe language spoken by most laser printers, imagesetters, and platesettersonly understands objects which are completely opaque. So InDesign (or any application which works natively with transparency) must take the transparent objects and break them into lots of different non-transparent pieces; this process is called

flattening . The result is a single opaque page that comes out of the printer.

You can control the way flattening occurs by choosing a

transparency flattener style , which we discuss below.

When Flattening Happens

When you have transparent objects or graphics containing transparency on a page, flattening happens on three different occasions in InDesign:

• When you print, InDesign uses the flattening settings in the Advanced panel of the Print dialog box (see Chapter 95).




• When you export an EPS file, InDesign uses the flattening settings in the Advanced panel of the Export EPS dialog box (see Chapter 98).




• When you export a PDF file in the Acrobat 4 format, InDesign uses the flattening settings on the Advanced panel of the Export PDF dialog box (see Chapter 99). Acrobat 5 PDF format can include transparency so it doesn't have to be flattened.

Figure 94-1 shows four simple objects created in InDesign. Two of the shapes and the type have had their opacity reduced with the Transparency palette. To show the effect of flattening, which normally only appears when printed, we exported the file to an Acrobat 4 PDF file. Then we opened the PDF in Adobe Illustrator, where the flattened objects can be observed. To make the effect more apparent, we offset some of the objects so you can see that they were broken into pieces. Note that InDesign doesn't break up the type, but it does convert some of it into a clipping path.

Note that InDesign has to have your high-resolution linked graphics on hand at print time in order to flatten properly. That means printing transparency probably won't work properly if you're printing through an OPI server or if you use DCS images.

How Can You Tell There Is Transparency?

Don't get caught by surprise when objects get flattened. Anytime you have transparent objects or graphics containing transparency there are two signs you can look for to indicate there is transparency on a page or spread:

• A page which has transparency shows a checkerboard background on the Pages palette (see Figure 94-2). This is the same indicator for transparency in a Photoshop layer!

  
  

  Figure 94-2. A checkboard background on a page indicates transparency.

  
  

  

  
  



• When you preflight a document with transparency, the Summary panel lists the pages where there are "non opaque objects."