The Style Settings panel in the Gantry based theme administration interface provides several options for configuring the main built in stylistic aspects of the template.
Gantry also provides the ability for you to create your own custom presets based on any parameter in the theme administrator. You should determine which parameters you wish to configure to be a part of the presets.
With Gantry, the ability to assign a certain style to an individual page has never been easier and/or more efficient. Just follow these simple steps: