Minimum row height that can be set for a row in a table

Hi,

Can you please let us know what is the minimum row height that can be set for a row in a table ?

What does this minimum value depend on ?

When I created a new pdf with a table and when I set a row height below 20 ,there is no change when the table is rendered on the pdf document. (This was done with Aspose.pdf 4.2). Is there any restriction on the minimum row height ?

Praveen