This tutorial will show you how you can add more canvas area easily using the Crop tool in Photoshop.
Step 1: Open your image, zoom out (ctrl -), and press 'f', then set the background color for your canvas area. In this case, I want to add black canvas area to my photo. So I set my background color to black.
Step 2: Now choose your Crop Tool from your Tool Palette or by typing 'c'.. then drag out a cropping marquee border on your image. Don't worry about the size.
Step 3: Grab the corner point of your marquee border and drag outside the image area into the gray area. Position the border where you wan to add the canvas space.
Step 4: Press Enter, the grey area outside your image is now become black canvas space. From here, you can put a white border using stroke to your image, and add text in the bottom canvas area like my final image below..
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