Use LayoutTransform to transform a TextBlock
<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" HorizontalAlignment="Center" VerticalAlignment="Center"> <StackPanel> <Button> <TextBlock> <TextBlock.LayoutTransform> <ScaleTransform ScaleX="3" ScaleY="3" /> </TextBlock.LayoutTransform> Foo bar </TextBlock> </Button> </StackPanel> </Page>