-Now go to Edit>Preferences>Guides, Grid and Slices...
Use these settings:
Gridline Every: 100 pixels
Subdivisions: 1
-View>Show>Grid to show the grid or hit Ctrl + '
-Make a new layer and name it Break
-Zoom in to make this easier to see. Now use the Single Column Marquee Tool to select just to the left of the first grid line.
-Now hit D to reset your colors to Black and White. Hit Ctrl+Backspace To fill the selection with black. Then hit the Right Arrow Key to Nudge the selection one pixel to the right. Finally hit Alt + Backspace to fill the selection with white.
-Do this at each gridline. When you are done you should have 5 white lines and 5 black lines evenly spaced throughout your image.
-Now change the break layer's blend mode to Soft Light, then make a copy of it by dragging the layer into the new layers button. We make 2 copies so it will show up dark enough.