Adobe PostScript files contain programming to draw the image and may and usually do contain comments that describe the requirements and some of the structure of the file. The comments, called DSC, are intended to assist other programs to process the file without fully understanding the file. These comments are used, for example, by LaTeX and dvips when encapsulating (incorporating) an EPS file.

Slides and tranparencies are one class of PostScript material; they are the same class as other reports and documents. Illustrations are a separate class of PostScript material. Because of the extreme difficulties of making a file that can do both, these classes should be maintained as separate collections and used appropriately.

A page extracted from a paper, with the undesired material removed with White Out(tm) operations, is still an Adobe print file. This is so even if one changes the DSC comments to claim that it is an EPS file. Please see the warning About extracting illustrations from print files.

There are no foolproof, omnipotent, programmable, programmed or universally simple methods for fixing Adobe PostScript files! There is a mathematical proof of the Halting Problem which is the reason why such methods do not exist. `Fixing' includes changing PS into EPS, making a file universally printable or viewable, rearranging or removing graphic elements from an image, etc.

Methods do exist for specific situations such as Adobe PostScript files generated by specific versions of specific applications. Program do exist that can modify the output of a large number of versions of a large number of commerically available applications. This is not the general case.

Because in the general case, there are no simple reliable methods, methods for addressing some Adobe PostScripts which must be complex or unreliable are not presented in this document.