Blades and KCF - You'll need to look up how to "expand text to fit", using subforms and setting your text field parameters to expand. If you properly set this up, your text will continue to flow down the page as it should....avoiding those frustrating little "+" signs.
Text field, set to allow multiple lines and in the layout tab, the Y: axis is set to expand. Wrap this text field in a subform (either positioned or flowed, just ensure that the Y: axis in the layout tab is set to expand). Jump to your PDF preview tab and test it out....should work for you now.