columnsep
Columnsep is a length parameter used in TeX and LaTeX to control the horizontal space between columns on a page that uses multiple columns. In standard LaTeX layouts or in environments provided by packages such as multicol or multicols, text is arranged in parallel columns, and columnsep defines the gap between the right edge of one column and the left edge of the next. It is a glue-type length, meaning its effective width can stretch or shrink to help justify the layout within the available text area.
The value of columnsep is independent of the width of an individual column, which is given by
To adjust columnsep, a document author can set the length directly, for example with a command like
There is also a related parameter, columnseprule, which controls the width of a vertical line drawn between