Adobe Illustrator is one of the most versatile drawing tools a digital artist can use. The program is loaded with tools, effects and features that enable the digital professional to create dazzling vector images that are infinitely scalable with no loss of quality. If you begin an illustration in a horizontal orientation, yet change your mind and want to work on your artwork as a vertical canvas, rotating the artboard is a simple edit. In Illustrator CS5, artboards can be set to automatically rotate to match the chosen media size.
Open the Illustrator document you wish to rotate to a different orientation. For instance, open a vertical document to rotate it to a horizontal format.
Select "Document Setup" from the "File" menu.
Click the preferred orientation icon in the "Document Setup" window. Choose the opposite orientation of your current document. For instance, if your Illustrator file is "Portrait," click "Landscape," and vice versa. Click "OK."