At this time we do not support different column widths. Each column within the column/bar graph has the same width. This width is controlled by the 'Gap Between Bars' setting on the Spacing Tab, in Plot Details.
The suggestion to support variable width is in our development database for our programmers to consider implementing in a future version of the software.
has this issue been solved for the version 8.6.0? I'm interested in doing a column graph where each column has variable width? If yes, how can this be done?