12.2.5 Payment Check Template - how to increase the size of the font when the check is VOID

We have a custom check template for payments. When there is an overflow check, it prints "********************VOID VOID VOID VOID VOID********************"  for the amount paid but the font is VERY small.

In the template, the original code is:

<?choose:?><?when:PaymentStatus/Code='VOID_BY_OVERFLOW'?>********************VOID VOID VOID VOID VOID********************<?end when?><?otherwise:?>

I tried this (adding the font size):

<?choose:?><?when:PaymentStatus/Code='VOID_BY_OVERFLOW'?><font size="8">********************VOID VOID VOID VOID VOID********************</font><?end when?><?otherwise:?>

but the template terminates with the error message: org.xml.sax.SAXException: element font is not supported yet.

In the template, how can I enlarge the font so this line prints larger?