Photo Effects: Tearing A Photo To Reveal Another

Step 2: Duplicate The Background Layer

Next, we need to duplicate the Background layer because we're going to be filling the original Background layer with black in a moment, so press Ctrl+J (Win) / Command+J (Mac) to duplicate it. We can now see our duplicate above the original in the Layers palette, which Photoshop has named "Layer 1":

Step 3: Add More Canvas Space And Fill It With Black

Click on the Background layer in the Layers palette to select it. We're going to add more canvas space to the left and right of the image, and we're going to use the Crop Tool to do it. But first, press the letter D on your keyboard to quickly reset your Foreground and Background colors if needed, so black becomes your Foreground color (white becomes your Background color), and then press X on your keyboard to swap them, so black becomes your Background color. Select the Crop Tool once again. Then with the Background layer selected in the Layers palette, drag out a selection with the Crop Tool around the entire image.

When you release your mouse button, you'll see little square handles appear around the image, one in each corner, and one on the top, bottom, left and right. Hold down Alt (Win) / Option (Mac) and drag out either of the side handles to add more canvas space. Add an extra inch or so on either side (holding down the Alt/Option key moves both side handles at once as you drag):

Press Enter (Win) / Return (Mac) when you're done, and Photoshop will add your additional canvas space and will also fill it with black, since black is our Background color:

Step 4: Fill The Entire Background Layer With Black

Photoshop has filled the extra canvas space with black for us, and everything looks fine in our image, but if we look at our Background layer thumbnail in the Layers palette, we can see that only the extra canvas space has been filled with black. The photo itself is still there:

To fix that and fill the entire Background layer with black, press Alt+Backspace (Win) / Option+Delete (Mac), which fills the layer with the current background color (black in our case). Again, nothing looks different in the image itself, but the Background layer thumbnail in the Layers palette is now showing solid black: