Column width is traditionally called
measure by typesetters. For best legibility, typographic manuals suggest that columns should be wide enough to contain roughly 60 characters per line. One formula suggests multiplying the
point size of the font by 2 to reach how wide a column should be in
picas — in effect a column width of 24
ems. Following these guidelines usually results in multiple narrow columns being favored over a single wide column. Historically, books containing predominantly text generally have around 40 lines per column. However, this rule of thumb does not apply to more complex text that contain multiple images or illustrations, footnotes, running heads, folios, and captions.
Column contrast refers to the overall color or greyness established by the column, and can be adjusted in a number of ways. One way is to adjust the relationship between the width and height of the column. Another way is to make adjustments to the
typeface, from choosing a specific font, to adjusting weight, style, size and
leading. Column contrast can be used to establish hierarchy, to balance the page composition, and to visually activate areas of the page. ==Web layout==