It also allows the material to be cloned from one image and painted into another. Clone works on all image types and drawables, though perhaps with odd effect on indexed images. Then click somewhere else in the image just as you would a regular paint tool. This is the primary operating mode for the Clone tool. Sets the destination point, hold to draw with clone Uses Photo retouching and tweaking images into being tileable are two very common uses of the clone tool.
Clone is a particularly handy tool for photo retouching.
Since it allows you to very easily copy part of one image to another section of an image, it can be used to remove blemishes or to get rid of elements in the image that distract from its composition. Since it grabs material from the same image, it is possible to use clone to produce much more realistic effects than can be achieved any other way. For photo retouching it is usually best to try to clone from a spot as close to the destination as possible so that the lighting is more accurate. For this sort of work, it helps to use a fuzzy brush instead of a hard-edge one. Another common use of the clone tool is painting from patterns.