FontSubstitutionSettings class

Specifies font substitution mechanism settings.

To learn more, visit the Working with Fonts documentation article.

public class FontSubstitutionSettings


DefaultFontSubstitution { get; }Settings related to default font substitution rule.
FontConfigSubstitution { get; }Settings related to font config substitution rule.
FontInfoSubstitution { get; }Settings related to font info substitution rule.
FontNameSubstitution { get; }Settings related to font name substitution rule.
TableSubstitution { get; }Settings related to table substitution rule.


Font substitution process consists of several rules which are checked one by one in specific order. If the first rule can’t resolve the font then second rule is checked and so on.

The order of the rules is following: 1. Font name substitution rule (enabled by default) 2. Font config substitution rule (disabled by default) 3. Table substitution rule (enabled by default) 4. Font info substitution rule (enabled by default) 5. Default font rule (enabled by default)

Note that font info substitution rule will always resolve the font if FontInfo is available and will override the default font rule. If you want to use the default font rule then you should disable the font info substitution rule.

Note that font config substitution rule will resolve the font in most cases and thus overrides all other rules.


Shows how to access a document’s system font source and set font substitutes.

Document doc = new Document();
doc.FontSettings = new FontSettings();

// By default, a blank document always contains a system font source.
Assert.AreEqual(1, doc.FontSettings.GetFontsSources().Length);

SystemFontSource systemFontSource = (SystemFontSource) doc.FontSettings.GetFontsSources()[0];
Assert.AreEqual(FontSourceType.SystemFonts, systemFontSource.Type);
Assert.AreEqual(0, systemFontSource.Priority);

PlatformID pid = Environment.OSVersion.Platform;
bool isWindows = (pid == PlatformID.Win32NT) || (pid == PlatformID.Win32S) ||
                 (pid == PlatformID.Win32Windows) || (pid == PlatformID.WinCE);
if (isWindows)
    const string fontsPath = @"C:\WINDOWS\Fonts";

foreach (string systemFontFolder in SystemFontSource.GetSystemFontFolders())

// Set a font that exists in the Windows Fonts directory as a substitute for one that does not.
doc.FontSettings.SubstitutionSettings.FontInfoSubstitution.Enabled = true;
doc.FontSettings.SubstitutionSettings.TableSubstitution.AddSubstitutes("Kreon-Regular", new[] {"Calibri"});


// Alternatively, we could add a folder font source in which the corresponding folder contains the font.
FolderFontSource folderFontSource = new FolderFontSource(FontsDir, false);
doc.FontSettings.SetFontsSources(new FontSourceBase[] {systemFontSource, folderFontSource});
Assert.AreEqual(2, doc.FontSettings.GetFontsSources().Length);

// Resetting the font sources still leaves us with the system font source as well as our substitutes.

Assert.AreEqual(1, doc.FontSettings.GetFontsSources().Length);
Assert.AreEqual(FontSourceType.SystemFonts, doc.FontSettings.GetFontsSources()[0].Type);

See Also