Understanding the fundamental differences between Painting programs and other major DTP packages is a must if we are to:

1. use them efficiently.
2. appreciate the special requirements in computer configuration demanded by their use.

Photoshop 4⁺ originated on the Apple Macintosh and grew to be what is regarded as the worlds most popular Bitmap Photo-Retouching program, and is identical in power and appearance on both the most commonly used desktop, the PC Windows based computers and the Apple Macintosh. The Windows user has had the choice of several other cheaper major packages for sometime all having individual areas of supremacy, but because of the head start in development enjoyed by Photoshop especially on the Mac, probably the majority of professional users remain faithful to this very friendly and powerful program. (anyone remember Photostyler? It out did Photoshop in a couple of key areas)

Designers / Illustrators and Prepress technicians use the accurate colour correction and retouching controls available while the Designers / Illustrators often use the program to create artwork that may be incorporated within a design created by a Drawing program such as Corel Draw or Adobe Illustrator. Bitmaps (scanned photos or freehand paintings) differ in every way to vectorised drawings and a fair amount of experience is required to efficiently and predictably create or correct bitmaps suitable for high quality output processes. Usually, bitmaps are imported into page layout programs such as PageMaker or Quark Express or imported into drawing programs as suggested above, and become just a part of the overall design. Rarely are bitmaps used as the sole object printed to an imagesetter or laser printer.

Bitmap images also consume large amounts of Harddisk space (i.e. an A4 CMYK image @ 300ppi resolution = 33Mb) and, when opened and retouched in a program such as Photoshop, demand that a lot of System memory and Virtual memory be available to the program - a minimum of 3 times the size of the average large file is a common rule of thumb, (5 times is a minimum rule of thumb in the Graphic Arts Industry) - a consideration that must be taken into account when setting up a system for this purpose.