Using guides and the grid

Guides appear as lines that float over the entire image and do not print. You can move, remove, or lock a guide to avoid accidentally moving it.
The grid is useful for laying out elements symmetrically. The grid appears by default as nonprinting lines but can also be displayed as dots.
Guides and grids behave in similar ways:
• Selections, selection borders, and tools snap to a guide or the grid when dragged within 8 screen (not image) pixels. Guides also snap to the grid when moved. You can turn this feature on and off.
• Guide spacing, along with guide and grid visibility and snapping, is specific to an image.
• Grid spacing, along with guide and grid color and style, is the same for all images.
In ImageReady, you can use Smart Guides to help align shapes, slices, and selections. They appear automatically when you draw a shape, or create a selection or slide. You can hide Smart Guides if you need to.
To show or hide a grid or guides:
Do one of the following:
• (Photoshop) Choose View > Show > Grid.
• Choose View > Show > Guides.
• Choose View > Extras. This command also shows or hides (Photoshop) selection edges, target path, slices, and notes, or (ImageReady) selection edges, slices, image maps, text bounds, text baseline, and text selection. 
To place a guide:
1. If the rulers are not visible, choose View > Rulers.
Note: For the most accurate readings, view the image at 100% magnification or use the Info palette.
2. Create a guide:
• (Photoshop) Choose View > New Guide. In the dialog box, select Horizontal or Vertical orientation, enter a position, and click OK.
• (ImageReady) Choose View > Create Guides. In the dialog box, specify guide options and click OK.
• Drag from the horizontal ruler to create a horizontal guide.



Dragging to create a horizontal guide
• Hold down Alt (Windows) or Option (Mac OS), and drag from the vertical ruler to create a horizontal guide.
• Drag from the vertical ruler to create a vertical guide.
• Hold down Alt (Windows) or Option (Mac OS), and drag from the horizontal ruler to create a vertical guide.
• (Photoshop) Hold down Shift and drag from the horizontal or vertical ruler to create a guide that snaps to the ruler ticks.
The pointer changes to a double-headed arrow  when you drag a guide.
To move a guide:
1. Select the Move tool , or hold down Ctrl (Windows) or Command (Mac OS) to activate the Move tool. (This option does not work with the Hand tool or the Slice tool .)
2. Position the pointer over the guide (the pointer turns into a double-headed arrow).
3. Move the guide in any of the following ways:
• Drag the guide to move it.
• Change the guide from horizontal to vertical, or vice versa, by holding down Alt (Windows) or Option (Mac OS) as you click or drag the guide.
• (Photoshop) Align the guide with the ruler ticks by holding down Shift as you drag the guide. The guide will snap to the grid if the grid is visible and View > Snap To > Grid is selected.
To lock all guides:
Choose View > Lock Guides.
To remove guides from the image:
Do one of the following:
• To remove a single guide, drag the guide outside the image window.
• To remove all guides, choose View > Clear Guides.
To hide Smart Guides (ImageReady):
View > Show > Smart Guides.
To turn snapping to guides on or off:
Choose View > Snap To > Guides.
To turn snapping to the grid on or off:
Choose View > Snap To > Grid. 
To set guide and grid preferences (Photoshop):
1. Do one of the following:
• In Windows, choose Edit > Preferences > Guides, Grid, & Slices.
• In Mac OS, choose Photoshop > Preferences > Guides, Grid, & Slices.
2. For Color, choose a color for the guides, the grid, or both. If you choose Custom, click the color box, choose a color, and click OK.
3. For Style, choose a display option for guides or the grid, or both.
4. For Gridline Every, enter a value for the grid spacing. For Subdivisions, enter a value to subdivide the grid.
If desired, change the units for this option. The Percent option creates a grid that divides the image into even sections. For example, choosing 25 for the Percent option creates an evenly divided 4-by-4 grid.
5. Click OK.