Hi Carol,
you can use the maxH property together with the vScrollPolicy property.
Designer will create a warning sing, but the field will do what you want.
Select your field ad then switch into the XML Source view.
Add the maxH property into the <field> tag.
Here an example of a field that is initially 150x20 mm and can grow up to 50mm height, but doesn't allow to enter texts that wont be visible in the visible area of the maximum field size.
<field name="TextField1" y="10mm" x="10mm" w="150mm" minH="20mm" maxH="50mm">
<ui>
<textEdit multiLine="1" hScrollPolicy="off" vScrollPolicy="off">
<border>
<edge stroke="lowered"/>
</border>
<margin/>
</textEdit>
</ui>
<font typeface="Myriad Pro"/>
<margin topInset="1mm" bottomInset="1mm" leftInset="1mm" rightInset="1mm"/>
<caption reserve="25mm">
<value>
<text>Text Field</text>
</value>
</caption>
</field>