TIPS FOR GUIDES & RULERS

by Trevor Morris

1. While dragging guides, hold down the Alt key to switch between vertical and horizontal guides. Alt-click on an existing vertical guide to change it into a horizontal guide, and vice versa. Note: Guides are created by dragging them out from the document rulers, so ensure that therulers are turned on [Ctrl+R] (View » Show Rulers).
2. Dragging guides with the Shift key held down will force them to snap to the ruler increments (markings).
3. Double-click on guides to open the Guides & Grid Preferences [Ctrl+K, Ctrl+6] (File » Preferences » Guides & Grid...).
4. Double-click on the rulers [Ctrl+R] to open the Units & Rulers Preferences [Ctrl+K, Ctrl+5] (File » Preferences » Units & Rulers...). Tip: You can also select a new unit of measurement from the Cursor Coordinates pop-up menu on the Info palette [F8] (Window » Show Info).
5. Center the ruler origin anywhere on the canvas by dragging from the top-left corner (where the Rulers [Ctrl+R] meet); reset the origin to its default position by double clicking on the top-left corner.
6. Use paths to create curved or diagonal guides. Simply draw a path using the Pen tool [P] and use it as a guide while drawing or painting (the path will remain visible). Tip: Use the Hide Path command [Ctrl+Shift+H] (View » Hide Path) to toggle the visibility of a path.

Guides snap not only to the edges (left, right, top and bottom) of the active layer or selection, but also to the vertical and horizontal center (of the current layer or selection). The opposite is also true: you may snap a selection or layer to an existing guide (either by edge or center).Note: Guides do not snap to the Background layer. Also, be sure that Snap To Guides [Ctrl+Shift+ ; ] (View » Snap To Guides) is turned on for the above tip to work! Tip: Find the center of the canvas by filling [Shift+Backspace] (Edit » Fill...) a New Layer [Ctrl+Shift+N] (Layer » New Layer...) and snapping a guide to the vertical and horizontal centers.