ParagraphSpacing is an option for Cell, StyleBox and StyleForm which specifies how much extra space to leave between successive paragraphs of text.
ParagraphSpacing->
c
,
0
leaves an extra space of c times the height of the font in the paragraph.
ParagraphSpacing->
0,
n
leaves an extra space of exactly n printer's points.
ParagraphSpacing->
c
,
n
leaves an extra space of c times the height of the font plus n printer's points.
Paragraph breaks are taken to occur whenever an explict Return character appears in a block of text.
ParagraphSpacing is added to LineSpacing to determine spacing between paragraphs.
A typical default setting is ParagraphSpacing->{0,
0}.
ParagraphSpacing applies only to ordinary text, not Mathematica expressions.
Extra space specified by ParagraphSpacing is inserted before the first line of each paragraph. No extra space is inserted if the paragraph is at the beginning of a cell or a string.
c
,
0
leaves an extra space of c times the height of the font in the paragraph. 
0,
n
leaves an extra space of exactly n printer's points. 
c
,
n
leaves an extra space of c times the height of the font plus n printer's points. 
