Adobe InDesign CS3 Bible

Typically, you'll want to directly export your InDesign files to PDF format rather than create a PostScript file and translate to PDF using the separate Adobe Acrobat Distiller product. First, I'll show how to export, then I'll explain how to print to PDF on those occasions when that's the better option.

Exporting PDF files

An easy way to create a PDF file from InDesign is to export it by choosing File ‚ Export, or pressing z +E or Ctrl+E. You'll get the Export dialog box, which like any standard Save dialog box lets you name the file and determine what disk and folder the file is to be saved in. The key control in the Export dialog box is the Formats pop-up menu, where you choose the format (in this case, Adobe PDF).

Tip ‚  

The fastest way to create a PDF file is to choose File ‚ PDF Export Presets and then select a preset from the submenu. There are seven presets optimized for different output needs. You can also add your own, as explained a bit later in this chapter. When you select a preset from the submenu, you then see the Export dialog box. Choosing a preset defaults the Formats pop-up menu to Adobe PDF and preconfigures the PDF export settings covered in the following sections.

Tip ‚  

If you're working with the InDesign Books feature (see Chapter 9), you can export the book's chapters to PDF files from an open book's pane, using the Export Book to PDF option in its palette menu. (If one or more documents in the book are selected in the pane, the menu option will change to Export Selected Documents to PDF.) The setup options are the same as for exporting individual documents.

After you've selected Adobe PDF in the Export dialog box's Formats pop-up menu, and given the file a name and location, click the Save button to get the Export PDF dialog box, shown in Figure 32-1. The dialog box has six panes, with General being the one displayed when you open the dialog box. There are several options that are accessible from all six panes:

Figure 32-1: The Export PDF dialog box's General pane.

The General pane

Use the General pane to determine what is exported. The pane has three sections: Pages, Options, and Include.

In the Pages section, you can set the following options:

In the Options section, you can set the following options:

In the Include section, you can set the following options:

The Compression pane

All the options in this pane, as shown in Figure 32-2, compress your document's graphics. For documents you're intending to print professionally, make sure that for all three image types, No Sampling Change is selected and that Compression is set to None. You don't want to do anything that affects the resolution or quality of your bitmap images if you're outputting to a high-resolution device.

Figure 32-2: The Export PDF dialog box's Compression pane.

But it's fine to check the Crop Image Date to Frames option, since this discards portions of pictures not visible on-screen, reducing file size and reducing processing time during output ( imagesetters and other devices usually have to process the entire image, even if only part of it is actually printed).

It's also fine to check the Compress Text and Line Art option. It compresses vector graphics (both imported and those created in InDesign) as well as text, but does so without affecting output quality.

The compression settings are more appropriate for documents meant to be viewed online, as the sidebar "Settings for on-screen usage" explains later in this chapter. You usually leave the image downsampling at 150 pixels per inch (ppi) for color and gray-scale images, and at 300 ppi for black-and-white images. Even though a computer monitor's resolution is 72 ppi, you want enough resolution so when a reader zooms in that the images are still clear. A good rule of thumb for documents to be printed is that the downsampling or subsampling ppi for color and gray-scale images should be at least double the printer's lpi.

For the Image Quality setting for images, Medium quality is fine for on-screen documents, but not for documents you intend to let readers print or that will be output at a service bureau. A rule of thumb is to choose High if the documents will be printed on an ink-jet or laser printer, and Maximum if they will be printed at an imagesetter or other high-end output device.

Note that JPEG compression is lossy, meaning it discards data to save space. That's why its Image Quality settings are characterized with subjective terms like Low, Medium, and High. Zip compression is lossless, so no image detail data is discarded. Instead, you limit the color depth by choosing between 4-bit (16 colors) and 8-bit (256 colors).

The Tile Size check box and field determine the size of the tiles for progressive display. For large images, this option will show subsequent pieces, or tiles, of the image, until the full image has been displayed, so the reader has a visual indication that the page is in fact loading. This option is only available when Compatibility is set to Acrobat 6 (format version 1.5) and Compression is set to JPEG2000. You can change the size of the tile from the default of 256 pixels.

Understanding compression methods

The act of choosing a compression method for the color, grayscale, and monochrome images in a PDF is simple ‚ you just pick something from a menu in the Compression pane of the Export PDF dialog box. The challenge is in knowing what to pick. Take a look at the type of images the compression methods work best for, and then choose the one that represents the bulk of the images in your layout.

Downsampling and subsampling accomplish similar goals, but use different mathematic techniques to do so. When you reduce the dpi, you're essentially throwing away image data to make it smaller ‚ for example, replacing a 100-by-100-pixel image with a 25-by-25-pixel version reduces the file size to 1 / 16 . Downsampling averages adjacent pixels' colors and replaces the cluster of adjacent pixels with one averaged pixel as it reduces the image size. (There are two methods for downsampling: bicubic and average. Bicubic usually, but not always, results in a truer image. Average downsampling tends to work better in nonphotographic images, with less-minute detail.) Subsampling does no averaging; it simply throws away pixels in between the ones it retains. Downsampling looks better for photographic images with lots of detail and color; subsampling looks better for images with clear color differences and few intricate details.

For prepress purposes, the resolution should be one and a half to two times the line screen ruling used to print the file. For on-screen purposes, keep in mind that higher resolutions are better when users need to increase the view scale in the PDF (for example, if they need to see detail in a map). In the Acrobat support section of www.adobe.com , you can find more details about specific image resolutions that work well with printer resolutions.

 

Marks and Bleeds pane

Use this pane, shown in Figure 32-3, to set the page bleed and printer's marks.

Figure 32-3: The Export PDF dialog box's Marks and Bleeds pane.

You typically set printer's marks only for files meant to be output on an imagesetter or other prepress device. Typically, you should select All Page Marks. Your Offset amount should be the same as or more than the bleed amount ‚ if your Offset is less than the bleed, it's possible the marks could appear in your page's margins.

If you have elements bleeding off the page, you'll want a Bleed setting of at least 0p9 (0.125 inch) ‚ that builds in enough forgiveness so that, when the pages are folded and trimmed , any elements that bleed off the page will, in fact, do so even if there's a slip in the page alignment.

If you specified a slug area (which specifies space for the printing of printer's marks) in the New Document (File ‚ New ‚ Document, or z +N or Ctrl+N) or Document Setup (File ‚ Document Setup, or Option+ z +P or Ctrl+Alt+P) dialog boxes, check Include Slug Area to reserve that space in your PDF file.

Likewise, if you specified bleed settings in the New Document or Document Setup dialog boxes, you can have InDesign use those settings by checking the Use Document Bleed Settings option.

Cross-Reference ‚  

These marks, bleed, and slug options are the same as for direct printing and are covered in detail in Chapter 31.

The Advanced pane

Use the Advanced pane, shown in Figure 32-4, to manage color calibration, font embedding, Open Prepress Interface (OPI) image substitution, and transparency flattening.

Figure 32-4: The Export PDF dialog box's Advanced pane.

The Color and PDF/X sections are where you control color calibration, as follows :

The Fonts section lets you control which fonts are included in the PDF file. Including fonts increases the file size but ensures that the document will display or print correctly, no matter if the recipient has the same fonts the document uses. The Subset Fonts When Percent of Characters Used Is Less Than field tells InDesign how to embed fonts in the exported PDF file. The default value of 100% tells it to include the entire font for each typeface used. This is the best option because it ensures that if your service bureau needs to edit the file later, the file will include all font information. If you choose a lower value and the service bureau changes some text, there's a chance that some characters used in the editing won't be in the file.

The value is a threshold, telling InDesign that if the file uses less than that percentage of the font's characters, to embed just the characters used; or, if the file uses more than that percentage, to embed them all. If your document uses many fonts but just a few characters in each, you might want to pick a value like 35%, since chances are less that you have typos in such documents (they tend to be ads and posters that are heavily proofed beforehand).

You can use a lower threshold for documents intended to be viewed solely on-screen, since you don't expect readers to edit the files. In fact, you may lock the file to prevent such modification.

Note ‚  

Some fonts can be locked, preventing their inclusion in PDF files. To avoid that problem, simply don't use them.

In the OPI section, use the three options in the Omit section to strip out EPS, PDF, and/or bitmap images ‚ you would use this only if you had high-resolution or color-corrected versions of these files at a service bureau and wanted them to substitute those files for the lower-resolution placeholder files you used during layout.

In the Transparency Flattener section, you can select a transparency preset, as well as override any transparency settings applied to individual spreads. Transparency flattening reduces the complexity of documents that have lots of transparent and semitransparent objects overlapping each other, which can dramatically increase output time and even prevent printing.

Cross-Reference ‚  

See Chapter 31 for more on OPI and transparency flattening

Security pane

The Security pane, shown in Figure 32-5, has no relevance to documents intended to be output at a service bureau or commercial printer, so make sure the Require a Password to Open the Document and Use a Password to Restrict Printing, Editing, and Other Tasks options are unchecked.

Figure 32-5: The Export PDF dialog box's Security pane.

These settings are useful if you're publishing the document electronically, since they control who can access the document and what they can do with the document once open. Here's how they work:

Using the Summary pane

The final Export PDF dialog box pane is the Summary pane, shown in Figure 32-6. It simply lists your settings all in one place for easy review. The only option ‚ Save Summary ‚ saves the settings to a file so you can include it with your files when delivering them to a service bureau, or for distribution to other staff members so they know the preferred settings.

Figure 32-6: The Export PDF dialog box's Summary pane.

Settings for on-screen usage

If your output is destined for use on a monitor ‚ such as via CD, on the Web, or in a corporate intranet, the settings you choose will differ from the print-oriented ones described in the "Exporting PDF files" section. Here's what you need to do:

 

Printing to PDF format

Sometimes, you may want to create a PDF file when printing, such as to save printer-specific options in the file. Note that, using this method, you'll need the $449 Adobe Acrobat Professional software to create a PDF file for prepress output, or the $299 Acrobat Standard for documents meant for display on-screen and printing on ink-jet, laser, and other medium-resolution printers. Both include the Acrobat Distiller program that creates PDF files. (The free Acrobat Reader is only for viewing PDF files.)

Set up your Print dialog box settings as described in Chapter 31. But don't click the Print button. Instead, follow these steps:

  1. Whether you use a Macintosh or a Windows PC, open the Acrobat Distiller program.

    For Acrobat Distiller 4 and 5, choose Settings ‚ Job Options to set the output options. For Acrobat Distiller 6, choose a setting from the Default Settings pop-up menu in the Acrobat Distiller dialog box. Then go back to the InDesign Print dialog box.

  2. On the Mac, click the Printer button, choose the Output Options menu item from the pop-up menu in the resulting dialog box, then check the Save as File Option, choose the file format (PDF) from the Format pop-up menu, and click Save. You'll get the Save to File dialog box, where you choose the filename and location, then click the Save button to save the file. In Windows, select Acrobat Distiller from the Printer pop-up menu. Then click the Print button. In a few seconds, a new window will open up asking for a filename and file location. After choosing those, click the Save button.

    Note ‚  

    You can also create PDF files by exporting to an EPS or PostScript file, then using the Acrobat Distiller program to convert the file to PDF format. There's no need to do this if you have InDesign unless you happen to have EPS or PostScript files you've previously generated that you'd rather convert to PDF via Distiller than find the InDesign originals and export PDFs from InDesign. You can, of course, use Distiller to create PDFs from any PostScript or EPS file, no matter what program created it.

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