output.xaml

<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
  <Window.Resources>
    <Storyboard x:Key="storyboard">
      <DoubleAnimation From="1" To="0" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="pesho" />
    </Storyboard>
    <SomeConverter x:Key="myConverter" />
    <Int32 x:Key="myConverterParam">20</Int32>
  </Window.Resources>
  <Button Content="Pesho" x:Name="pesho" x:Uid="pesho">
    <Button.Style>
      <Style TargetType="Button">
        <Setter Property="FontSize">
          <Setter.Value>
            <Binding Path="PresenterFontSize" Converter="{StaticResource myConverter}" ConverterParameter="{DynamicResource myConverterParam}" />
          </Setter.Value>
        </Setter>
        <Setter Property="FontWeight" Value="Bold" />
        <Setter Property="Template">
          <Setter.Value>
            <ControlTemplate TargetType="Button">
              <Grid>
                <ContentPresenter />
              </Grid>
            </ControlTemplate>
          </Setter.Value>
        </Setter>
      </Style>
    </Button.Style>
  </Button>
</Window>