Dot shape: Choice of dot shape—square, round, or elliptical — is determined by both press requirements and aesthetics. Square dots, which are the most common, are thought to give the best definition of fine detail but may cause midtone "chop" or roughness in large, smooth areas such as skies. For jobs where these tones are particularly important, elliptical or chain dots may be used. Because 50% elliptical dots connect only at their ends, they also mitigate the effects of dot gain, yielding smoother gradation among adjacent tonal areas and reducing "tone breaks" or rough textures in, for example, skin tones. When heavy dot gain is predictable, such as on newsprint or on highspeed web applications, the best choice may be round dots. They do not connect until they reach about 70 percent of maximum size; thus, they extend midtone range and minimize loss of midtone and highlight quality.