To enable collaboration without compromising the integrity of a document and maintaining portability at the same time, Acrobat includes a feature called comments. Comments are annotations that you or your peers can make to a PDF file without altering it. Think of them as electronic sticky notes that you or your peers can add anywhere on a page as part of a document revision process. You can resize them, make them invisible, have your printer ignore them or print them, add replies to them, and export their contents to a separate text file for review.
Comments go way beyond the sticky note model, however. Besides Notes Acrobat also gives you the ability to insert file and audio attachments to meet your different needs.
The greatest advantage of using comments, as opposed to doing reviews on a JPEG file, is that Acrobat uses a special separate layer for the comments; the pages themselves are not altered. You can hide all the comments and the page looks like it did before you added them.
Commenting tools are available from the Comments, Commenting Tools menu or through the Commenting toolbar. To activate the Commenting toolbar choose View, Toolbars, Commenting.
The basic sticky note is the most common type of comment. To create a Note select the Note tool from the Commenting toolbar or select the Comments, Commenting Tools, Add a Note option. With the Tool selected, click anywhere in the document where you want your Note to appear. You will see a small "call box" icon where you clicked and the Note beside it. Click inside the Note and type away.
You can use Notes to type a quick message, give instructions, ask questionsyou name it. Because these notes can get quite large, they minimize when not focused on, leaving the small icon in their place. Click on that icon to open the note again. You can select what icon you want from a list in the Note Properties dialog, as well as adjust color, transparency, and more (see Figure 42.12). To access the Note Properties dialog, click the Options button and select Properties from the pop-up menu.
Figure 42.12. The basic Note comment.
There are times when the written word or the most ambitious doodling aren't enough. Acrobat gives you the option to add voice annotations to your document with the Record Audio Comment tool. To use it, choose Comments, Commenting Tools, Record Audio Comment or click the Record Audio Comment button in the Commenting toolbar. With the Record Audio Comment tool selected, click anywhere in the page, click the red Record button in the Recorder dialog, and start talking. Of course, a microphone is required (see Figure 42.13). You can also use an existing audio track in WAV or AIFF formats.
Figure 42.13. Access the context menu and select Play File to listen to audio messages.
After you finish recording or inserting your audio file, Acrobat displays a small speaker-shaped icon on the page.
Although file attachments are not really comments, Acrobat considers them so. Files attached to a PDF work in the same way as files attached to an email message. Attached files can be of any format.
To attach a file to a PDF, use the Attach a File as a Comment button in the Commenting toolbar or select the option from the Comments, Commenting Tools menu. When attaching a file, Acrobat makes a copy of the file and embeds it within the PDF file. Mind you, this is not the same as placing an image in a PDF. Acrobat doesn't display the attached files.
When creating the attachment, you are given an option to select between different types of icons (a paper clip, a thumbtack, a tag, or a chart) to display on the page. Your peers can click the icon to extract the attachment (see Figure 42.14).
Figure 42.14. Attached files can be extracted and saved from the context menu.