Step 5: Turn On Photoshop's Grid

We're going to create our vertical and horizontal strips, and to help us out, we'll use Photoshop's grid. Go up to the View menu at the top of the screen, choose Show, and then choose Grid. You can also use the keyboard shortcut Ctrl+' (Win) / Command+' (Mac) to easily turn the grid on and off. When your grid appears, if you find that you can't see it very well because the grid color is blending in with the colors of your image, press Ctrl+K (Win) / Command+K (Mac) to quickly bring up Photoshop's Preferences. Then, from the drop-down menu at the top, choose Guides, Grid and Slices. From here, we can change the color of the grid. In the Grid options, click on the color swatch in the top right corner, which will bring up Photoshop's Color Picker. Select a color for your grid that you'll be able to see in front of your image and then click OK to exit out of the Color Picker. You can see in the screenshot below of the Grid options that I've changed my grid color to yellow:

Click OK to exit out of the Preferences dialog box. You should now see your grid in your new color (in my case yellow) over top of your image:

Step 6: Drag Out A Series Of Horizontal Selections

Let's create our horizontal strips first. Grab your Rectangular Marquee Tool from the Tools palette, or press M on your keyboard to quickly select it:

Now let's use our grid to help us create our horizontal strips. First, make sure the "Horizontal Strips" layer is selected in the Layers palette (the currently selected layer is highlighted in blue). I'm going to create horizontal strips that are two grid rows high, with one grid row separating them from each other. Now, I want to make sure that the woman's eyes are included in the final effect, so I'm going to start by dragging out a selection around the two grid rows in front of her eyes. By default, my selection will snap to the grid as I'm dragging to make things easy. If you find that your selection is not snapping to the grid, go up to the View menu at the top of the screen, choose Snap To, and then choose Grid. You should see a checkmark to the left of the word "Grid".

Here's my selection around the two grid rows in front of her eyes:

This selection will become one of our horizontal strips. Now let's create the rest of them. Hold down your Shift key, which will tell Photoshop to add these next selections to our original selection, and drag out more horizontal selections, keeping each one two grid rows high and leaving one grid row separating each selection. Your image should look like this when you're done:

Step 7: Add A Layer Mask

With our horizontal selections in place, click on the Layer Mask icon at the bottom of the Layers palette to add a layer mask to the "Horizontal Strips" layer:

Photoshop adds a mask to the layer and uses the selections we've created to determine which parts of the layer will remain visible and which parts will become hidden from view. The areas that were inside our horizontal selections remain visible, while the areas that were in the grid columns that separated our selections disappear, revealing the black-filled layer underneath:

I'm going to press Ctrl+'(Win) / Command+' (Mac) to temporarily hide my grid so we can see more clearly what's happened. We've now created our horizontal strips: