Adobe 22020737 Acrobat X Pro Manual - Page 400

USING ACROBAT X PRO 394 Color management In general, you have the following choices for handling colors when creating PDFs: • (PDF/X-3) Does not convert colors. Use this method when creating a document that will be printed or displayed on various or unknown devices. When you select a PDF/X-3 standard, color profiles are automatically embedded in the PDF. • (PDF/X-1a) Converts all colors to the destination CMYK color space. Use this method if you want to create a pressready file that does not require any further color conversions. When you select a PDF/X-1a standard, no profiles are embedded in the PDF. Note: All spot color information is preserved during color conversion; only the process color equivalents convert to the designated color space. More Help topics "Using a safe CMYK workflow" on page 390 Working with color profiles About color profiles Precise, consistent color management requires accurate ICC-compliant profiles of all of your color devices. For example, without an accurate scanner profile, a perfectly scanned image may appear incorrect in another program, simply due to any difference between the scanner and the program displaying the image. This misleading representation may cause you to make unnecessary, time-wasting, and potentially damaging "corrections" to an already satisfactory image. With an accurate profile, a program importing the image can correct for any device differences and display a scan's actual colors. A color management system uses the following kinds of profiles: Monitor profiles Describe how the monitor is currently reproducing color. This is the first profile you should create because viewing color accurately on your monitor allows for critical color decisions in the design process. If what you see on your monitor is not representative of the actual colors in your document, you will not be able to maintain color consistency. Input device profiles Describe what colors an input device is capable of capturing or scanning. If your digital camera offers a choice of profiles, Adobe recommends that you select Adobe RGB. Otherwise, use sRGB (which is the default for most cameras). Advanced users may also consider using different profiles for different light sources. For scanner profiles, some photographers create separate profiles for each type or brand of film scanned on a scanner. Output device profiles Describe the color space of output devices like desktop printers or a printing press. The color management system uses output device profiles to properly map the colors in a document to the colors within the gamut of an output device's color space. The output profile should also take into consideration specific printing conditions, such as the type of paper and ink. For example, glossy paper is capable of displaying a different range of colors than matte paper. Most printer drivers come with built-in color profiles. It's a good idea to try these profiles before you invest in custom profiles. Document profiles Define the specific RGB or CMYK color space of a document. By assigning, or tagging, a document with a profile, the application provides a definition of actual color appearances in the document. For example, R=127, G=12, B=107 is just a set of numbers that different devices will display differently. But when tagged with the Adobe RGB color space, these numbers specify an actual color or wavelength of light-in this case, a specific color of purple. Last updated 10/11/2011