How to Set Up Guides, Grids, and Slices in Photoshop CS6
Guides are nonprinting lines you can create on your Photoshop screen to make it easier to align objects. Grids are vertical and horizontal lines in the background that make lining up objects even easier. Slices are sections of an image you can create for web page graphics so that each slice can be loaded and treated separately (usually in a table or similar arrangement).
In the Guides and Smart Guides areas, you can set these options:
Color: Either select a color from the drop-down list or click the color sample swatch to select your own color. You may want to change the default color if that color is too similar to a dominant color in your image.
Style (for guides only): Select from lines or dashed lines. If you work with images that contain many horizontal and vertical lines that extend across most of an image, dashed lines may be more visible.
In the Grid area, these are your options:
Color: Select a color from the drop-down list or click the color sample patch to define a specific hue.
Style: You can select lines, dashed lines, or dots.
Gridline Every: Select the distance between gridlines.
Subdivisions: Select the number of subdivisions for each gridline.
In the Slices area, these are your choices:
Line Color: From the drop-down list, select a color for the lines that surround each slice.
Show Slice Numbers: If you select this check box, Photoshop adds a slice number to the display of slices, which makes it easier to keep track of individual slices.