extending the editor

I have managed to extend the editor including with an indent action. For an action class that extends StyledEditorKit.StyledTextAction the key code is, MutableAttributeSet mutableAttributeSet = new SimpleAttributeSet(); StyleConstants.setLeftIndent(mutableAttributeSet, <indent value>); setParagraphAttributes(editor, mutableAttributeSet, false); But an attempt to set paragraph spacing similarly fails MutableAttributeSet mutableAttributeSet = new SimpleAttributeSet(); StyleConstants.setLineSpacing(mutableAttributeSet, 2.0f); setParagraphAttributes(editor, mutableAttributeSet, false); Does anybody have an idea why this doesn't work???