英语翻译
Shading:Avoid the use of shading,but if unavoidable,use a coarse rather than a fine screen setting (80-100 line screen is preferred).Avoid 1-20% and 70-99% shading; make differing shades vary by at least 20%,i.e.,25%,45%,65%.Instead of shading,denote variations in graphs or drawings by cross-hatching; solid black; or vertical,horizontal,or diagonal striping.Avoid the use of dots.