pango:layout-spacing (layout)

layout -- a pango:layout object
spacing -- an integer for the amount of spacing

The pango:layout-spacing function gets the amount of spacing in Pango units between the lines of the Pango layout. The (setf pango:layout-spacing) function sets the amount of spacing. When placing lines with spacing, Pango arranges things so that

line2.top = line1.bottom + spacing  

Since 1.44, Pango defaults to using the line height (as determined by the font) for placing lines. The spacing set with this function is only taken into account when the line-height factor is set to zero with the pango:layout-line-spacing function.