Adobe Photoshop is a powerful graphics and photo-editing application. In the area of photo-retouching, Photoshop gives you the ability to create an array of impressive effects, from removing warts and scars from photos to assembling several images into a single composite. You can also use Photoshop to create more subtle effects, such as adding scratches to a wall or other surface.
Load the image that you want to add scratches to onto your computer, either by transferring it from a camera or by scanning it in.
Open Photoshop. Select "File" from the menu and choose "Open." In the dialogue that appears, locate the image you want to use and open it.
Click on the "Create New Layer" button at the bottom of the "Layers" palette. Then click on the "FX" button and choose "Bevel and Emboss."
Set the "Style" to "Outer Bevel." Then make the "Depth 70" and the "Size 2." Click "OK."
Select the "Pencil" tool from the toolbar. In the options at the top, set the size to "1." Use the tool to draw in the scratches that you want on the wall. Save your work.