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Adobe illustrator cs4- P19

Adobe illustrator cs4- P19: Good designers have many tools at their disposal. Especially in an environment where most designers have other powerful graphics applications, it can be diffi cult to choose which one to use for a particular task. For example, a designer can apply soft drop shadows in Photoshop, Illustrator, and InDesign—is one application any better than the others for this? | 514 CHAPTER 15 PREPRESS AND PRINTING In truth transparency has always been around in raster form in Adobe Photoshop. The only difference now is that you can apply these effects in vector form and still edit them late in your workflow. At the end of the day these transparency effects will become rasterized leaving you with the same result as if you had done everything in Photoshop. In any case let s take a closer look at what transparency is and how it works. NOTE If you ve used Photoshop before you may be familiar with the term flattening which combines all layers in a document. Although similar in concept transparency flattening is different. Understanding Transparency Flattening Let s start with a simple fact PostScript doesn t understand transparency. As you probably know PostScript is the language that printers and RIPs speak. Native transparency is understood only by PDF language version 1.4 or newer first present in Acrobat 5 and Illustrator 9 . To print objects with transparency Illustrator must translate any transparent artwork into a language that PostScript understands. This translation process is called transparency flattening. The process of flattening is simple and Illustrator follows two cardinal rules when performing flattening on a file 1. All transparency in the file must be removed. 2. In the process of performing rule 1 the appearance of the file cannot change. Both of these rules are followed during the flattening process with no exception. Obviously all transparency has to be removed because PostScript doesn t know what transparency is. Additionally if removing the transparency would result in your file changing in appearance that would mean you could design something in Illustrator that couldn t be printed which doesn t make sense either. If you think about it if you re removing transparency from the file and you re also keeping the visual appearance of the object something has to give and that something is the editability of your file. Let s