Left aligned text , with a ragged right side, as used in this booklet, is better. This is also a good practice for headings, section titles, etcetera. It is easier to read and supports the reader in locating the text and moving to the next line more efficiently. Using a different sans serif font, bold, or larger font type is a better idea. Paragraphs are best with all text aligned to the left, avoiding the use of indents, and using a line space between paragraphs, will increase the ease of reading.
Word spacing is also important.
Maintain normal, even spacing, rather than condensing or stretching a word or line of words, just to fit the text into a specific space. Double columns should maintain left aligned, right ragged text format. Ensure there is sufficient mid-margin space so the two columns are clearly separated, to reduce reading across the whole page. Graphics are best positioned clearly within the text. Avoid wrap-around text formats which increases reading difficulty.