A simple method for creating cracks.
01. Take the image you will be applying cracks to. For demonstration purposes, the following image will be used.
02. Zoom in to the section of the image you want to apply cracks to.
03. Start by creating a new layer on top of the image. Select your brush tool with the following settings: size = 1px, mode = normal, opacity = 100%, flow = 75%, airbrush. Draw your cracks! Don't make them too smooth, keep them jagged and random.
04. Apply these white cracks to your whole image.
05. Once you are satisfied with your cracks, duplicate your cracks layer, and invert it. (Ctrl + I, Image --> Adjustments --> Invert) This will make a black cracks layer. Make sure your black cracks layer is above your white cracks layer.
06. Go to your white cracks layer, and nudge it one pixel down, and one pixel to the right. This will give your cracks depth.
07. Merge the white, and black cracks layers, and set the blending mode to 'Soft Light.'
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