Adobe 65023809 Printing Guide - Page 126

If you wish to further reduce the file size, choose Document > Reduce File Size. This also gives you the option to change the version compatibility of the PDF. Select the version compatibility that you need (or select the default option to Retain Existing format), and click OK. Note that reducing the version may change the content of the file. For example, converting a file from PDF 1.4 (Acrobat 5.0) to PDF 1.3 (Acrobat 4.0) compatibility requires transparency to be flattened. Note: You can also set version compatibility in PDF Optimizer. Using PDF Optimizer to optimize files for print Acrobat PDF Optimizer makes the PDF file more efficient and can be used to prepare it for printing. You can unembed fonts, compress images, correct the file format, remove components you no longer need in the file, and flatten transparency. Keep in mind how you intend to use the file. The options you choose in PDF Optimizer depend on your workflow. For high-resolution printing, use caution when downsampling or compressing images, unembedding fonts, or flattening transparency. Some options are more appropriate for a file that will be printed to a high-end printer, and others are more appropriate for a file that is intended for on screen viewing. In most cases, the default settings are appropriate for a variety of uses. Note: Optimizing a digitally signed document invalidates the signature. Optimizing a PDF/X file can invalidate the file if the resulting document no longer has its fonts embedded, or is compatible with PDF 1.4 (Acrobat 5.0) or later. To optimize a PDF file: 1. Choose Advanced > PDF Optimizer, or click the PDF Optimizer button ( ) in the Print Production toolbar. 2. Click Audit Space Usage to view a report of the total number of bytes used for specific document elements. The results appear in actual bytes and as a percentage of the total file size. Auditing the document can help you decide which options to select. 3. Select Images in the left pane of the dialog box, and choose options according to your output workflow. This option downsamples or compresses color, grayscale, and black-and-white images. Downsampling reduces file size by lowering the resolution of images. This is accomplished by averaging the colors of several pixels and merging them into larger pixels of the average color. Compression reduces file size by eliminating unnecessary pixel data. In general, JPEG gives better results on images such as photographs with gradual color transitions. ZIP is the better choice for illustrations with large areas of solid, flat color or patterns made up of flat colors. For monochrome images, JBIG2 compression, which is available in PDF Optimizer but not in Acrobat Distiller, is superior to CCITT. If you're using JPEG or JPEG2000 compression, specify maximum quality because JPEG and JPEG2000 compression methods are typically lossy, resulting in some permanent data loss. For JPEG2000 compression, you can also specify lossless so that no pixel data is removed. Compression for monochrome images is lossless, except for JBIG2 compression, which provides both lossy and lossless modes of compression. 4. Select Fonts in the left pane of the dialog box, to choose whether to unembed fonts to reduce file size. However, for high-end printing, Adobe recommends embedding all fonts. Check to make sure the font supplier allows embedding. 5. Select Transparency in the left pane of the dialog box, to flatten transparency in the document, using default options for Low, Medium, and High Resolution. If you saved a custom flattener style in the Flattener Preview, it's available here. For high-quality printing, it is best to use the High Resolution option or create a custom flattener style appropriate for your particular workflow system. 6. Select Discard Objects in the left pane of the dialog box to remove objects, such as embedded page thumbnails, bookmarks, and document tags from the PDF document. There are also options to convert smooth lines to curves and merge image fragments. Several of the options allow you to delete content that has nothing to do with imaging the document, such as JavaScript actions, search indexes, and form actions. The option to flatten form fields does not delete form field content, but flattens and embeds that content as visible artwork. Adobe Creative Suite 4 Printing Guide 124