The Print Variable Frame property is pictured below:



When unchecked, the field will be printed at the fixed height as set in the Form Editor. If the amount of text exceeds the size of the field, only the text that fits in the field will be printed - the rest will be cut off. The image below shows a print preview of what the field will look like in this case:



When checked, the field will expand vertically if the contents are greater than the size of the field. For example, several paragraphs of text will all be displayed even if the text field is only created to be a few lines high. The image below shows a print preview of what the field will look like in this case: