Dithering is a technique where patterns are applied to areas of color in a bitmap in order to simulate a wider color range. It works very well in pictures which contain a large number of colors. If you use dithering when you create a bitmap, it will not compress as well and will probably create a larger file. Xara LX offers three dithering options. For information on how to change the screen dithering, see Changing the screen dithering. Error-diffused dithering is a complex mathematical technique which, although slower, produces very high quality images.