Flexible line spacing with min-leading
By default, the paragraph line spacing is fixed to the value of the line-spacing characteristic. To allow flexible line spacing so that, for example, you can include inline graphics that are larger than the line spacing, set the min-leading characteristic to something other than its default value of #f. A useful value for min-leading is the same value as the line-spacing characteristic.
Use min-leading in a style specification, in a paragraph flow object, or where the characteristic will be inherited by a paragraph flow object.
(define para-style (style font-size: %bf-size% font-weight: 'medium font-posture: 'upright font-family-name: %body-font-family% min-leading: %bf-line-spacing% line-spacing: %bf-line-spacing%))