Use the Grid/Guides button to set up reference points when painting and to accurately place strokes on the image.
Use the field guides to provide reference points when painting, and the grid to help you accurately place strokes on the image. Neither the field guides nor the grids appear on the processed clip.
The Grid and Guides menu contains the Safe area guide controls, the Grid controls, and the Centre controls.
The Safe area guide controls and Centre controls are subsets of their corresponding controls in the Grid and Guides menu in the other tools.