The Grid and Guides

To help you position layers, Photoshop can display a grid, and you can also add ruler guides independently of the grid. As in page-layout programs, you can use the grid and the guides together in a hierarchical relationship: You can use the grid to mark the overall structure and spatial rhythm of your layout, while using guides to mark major divisions in your composition (Figure 8.3). Both the grid and guides have a snap-to option so that you can use them not only as a visual reference but also to make layer edges snap to the grid or guides.

Figure 8.3. Grid marking fundamental units of composition, and guides (red) marking printer margins in this example.