Font families vs postscript

Sorry for the late answer.

Each font has a postscript name as well as a pair of family & style properties. Postscript name uniquely identifies the font with one string and can be used as ID. A bundle of family and style also identifies the font, and they have a more readable form for a human.

Bold/italic properties are called "FauxBold" and "FauxItalic", they are responsible for emulating missing styles.

For example, if you have some well-known font like "Arial Bold", it means that boldness was applied manually by the font designer. And it looks good. Sometimes there is no bold style shipped, but you can emulate the same effect with the FauxBold property. It also looks good, but not as good as a manually designed font. The same thing applies to FauxItalic.

Inside a formatted text, you can achieve the same effects as well.

style = 'bold:true; italic:true'

In general, generating a postscript name is a bad idea. Sometimes "postscriptName" is not equal to "Family-Style". Here is as a sample how you can get font information from FontRegistry:

foreach (var fontInfo in FontRegistry.Installed.Fonts)
{
    Console.WriteLine(string.Format("Postscript: {0},  Family: {1}, Style: {2}", 
        fontInfo.PostscriptName, 
        fontInfo.Family, 
        fontInfo.Style));
}

Then you need to use family&style bundle for GUI elements and postscript name for making a rich text.