4. An article comprising computer memory encoded with instructions that, when executed, cause a computer to analyze legibility of text in an electronic document, wherein only three ratios are analyzed: a first ratio of tracking between letters in the text and character width; a second ratio of leading between lines of the text and average length of the lines; and a third ratio of visual luminance contrast between the letters and text background, the ratios analyzed independently of one another, each ratio compared to preset upper and lower legibility limits; wherein the lower and upper limits for the second ratio are 1:35 and 1:70.
4. An article comprising computer memory encoded with instructions that, when executed, cause a computer to analyze legibility of text in an electronic document, wherein only three ratios are analyzed: a first ratio of tracking between letters in the text and character width; a second ratio of leading between lines of the text and average length of the lines; and a third ratio of visual luminance contrast between the letters and text background, the ratios analyzed independently of one another, each ratio compared to preset upper and lower legibility limits; wherein the lower and upper limits for the second ratio are 1:35 and 1:70. 6. The article of claim 4 , wherein the memory is further encoded with an authoring tool for causing the computer to enter the text; wherein the text is analyzed as it is being entered.