Initializing QuickDraw GX Printing(IM:XP)

Inside Macintosh: QuickDraw GX Printing /: Chapter 2 - Core Printing Features / Using Core Printing Features

Initializing QuickDraw GX Printing
For your application to use QuickDraw GX, the user must be running system software version 7.1 or later. To test for the existence of QuickDraw GX printing features, use the Gestalt function. The Gestalt selector is gestaltPrintingMgrVersion ('pmgr'). The Gestalt function is discussed in Inside Macintosh: QuickDraw GX Environment and Utilities.

Note
The Gestalt selector for the entire QuickDraw GX feature set is gestaltGXVersion. This selector is discussed in Inside Macintosh: Environment and Utilities.
After you call the GXEnterGraphics function to initialize QuickDraw GX, you call the GXInitPrinting function to initialize QuickDraw GX printing features. The GXEnterGraphics function is discussed in Inside Macintosh: QuickDraw GX Environment and Utilities.
To terminate printing with QuickDraw GX, you must call the GXExitPrinting function. You can only use this function after you have successfully called the GXInitPrinting function and before you call the GXExitGraphics function to shut down QuickDraw GX:
OSErr err;
...
GXEnterGraphics();
err = GXInitPrinting(); /* Set up print facility */
if (!err)
   {
   /* The event loop and more initialization goes here */
   ... 
   }
GXExitPrinting();       /* Close QuickDraw GX printing. */
GXExitGraphics();