<Grid
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  Background="White"
  TextElement.FontFamily="Fonts/#Roboto"
  TextElement.FontSize="30"
  TextElement.Foreground="Black">
  
    <StackPanel Margin="50" VerticalAlignment="Center" HorizontalAlignment="Center" Orientation="Horizontal">
        <TextBlock Width="320" Height="270" FontSize="40" TextWrapping="Wrap" TextTrimming="CharacterEllipsis" Background="WhiteSmoke">
            <Span FontSize="60">Lorem </Span>
            <Bold>
                <Bold.Foreground>
                    <LinearGradientBrush StartPoint="0,0" EndPoint="0,1">
                        <GradientStop Color="Orange" Offset="0"/>
                        <GradientStop Color="Teal" Offset="1"/>
                    </LinearGradientBrush>
                </Bold.Foreground>
                ipsum dolor</Bold> sit amet, 
                <Italic>consectetur
                <Span>
                    <Span.Background>
                        <LinearGradientBrush StartPoint="0,0" EndPoint="1,0">
                            <GradientStop Offset="0" Color="Silver"/>
                            <GradientStop Offset="1" Color="Yellow"/>
                        </LinearGradientBrush>
                    </Span.Background>
                    adipiscing</Span>
                <Span Foreground="Red">elit</Span></Italic>.
                Fusce <Bold>dolor</Bold> justo, elementum sed convallis eu, cursus vel nisi.
        </TextBlock>
   </StackPanel>

</Grid>