Sometimes halftone effects are useful in graphic design applications. Halftone is essentially reproduction of an image where changes in tone are produced by changes in dot size and/or spacing. There are various halftone methods that come from the printing world such as staying in greyscale or using CMYK color models. Applying halftone effects to an image is fairly straight forward in Adobe Photoshop using the Apply Halftone Method, but not so straight forward in Gimp.
