Lorem ipsum dolor sit amet consectetur adipisicing elit. Sint est soluta sed hic beatae consequatur et neque, numquam eos nemo quidem aliquid veniam incidunt ad iste placeat veritatis laboriosam tempore. Lorem ipsum
Anything from 45 to 75 characters is widely regarded as a satisfactory line length for a single-column page set in a serifed text face in a text size. The 66-character line (counting both letters and spaces) is widely regarded as ideal. For multiple column work, a better average is 40 to 50 characters.
—Robert Bringhurst