You drag a matrix column to just the right width, then switch a field parameter slicer or the data refreshes — and Power BI throws your sizing away and auto-fits everything again. Dragging borders in Desktop only holds until the next change, so a tidy table never stays tidy. This skill lets you set the exact pixel width you want, locks it in so auto-fit can't override it, and remembers every width — so when Power BI does drift, one command snaps them all back into place. It even spots field parameters and locks each option's own width, so every view of the table keeps its layout — run it with /column-width.