Staff Properties, Size
and Borders, Change Borders
Use Staff Borders to change line thickness of a staff's grid and to change the distance between limb groups.
To change the distance between limb groups,
type a new value in the Space between Groups edit field.
To set the line thickness for bar lines and cell split lines,
choose the line style, you want to change: Regular, Medium or Thick. The
choose by which factor the regular line width should be multiplied for that
style.
When changing the line thickness, it may be necessary to adjust the distance of bar lines to the cell borders.
Note: In most cases, the multiplication factor should be left at 1.0 for the Regular style.