A non-printing, non-exporting grid can be displayed on your page to help you lay out layer content more accurately.
Grids can be automatic or fixed—the former (as default) changes the frequency of grid subdivisions as you zoom in/zoom out, the latter always keeps the grid frequency constant (irrespective of zoom level).
Both grids are overlaid over your page and work best when combined with snapping, in particular when the Snap to Grid option is enabled. They will line up perfectly with rulers (when switched on) and, to alleviate poor contrast in some designs, can have a different color from the default gray color.
With the Zoom Tool selected, do one of the following:
At all zoom levels the grid shows as grid 'blocks' further split into grid subdivisions.
To make grid setup quick and easy, one of several grid presets can be chosen depending on how you plan to work.
The options will be in effect immediately.
The custom preset is in effect immediately.
When working with images at large magnification levels, zooming in an undetermined amount, a pixel grid serves as a handy visual aid. Pixel art, detail retouching and working with selections are just some examples of its use. A different grid color can also aid work where there is little color variance in the image.