I get a SerializationException: (...) is not marked as serializable. error in the following code:

[Serializable]
public class Wind
{
    public MyText text;
    public Size MSize;
    public Point MLocation;
    public int MNumber;

    /.../
}

[Serializable]
public class MyText 
{
    public string MString;
    public Font MFont;
    public StringFormat StrFormat;
    public float MySize;
    public Color FColor, SColor, TColor;
    public bool IsRequest;
    public decimal MWide;

    /.../
}

and the List to be serialized:

 List<Wind> MyList = new List<Wind>();

Code Snippet:

 FileStream FS = new FileStream(AppDomain.CurrentDomain.BaseDirectory + 
                                "Sticks.dat", FileMode.Create);
 BinaryFormatter BF = new BinaryFormatter();

 BF.Serialize(FS, MyList);  
 FS.Close();

throws an Exception:

System.Runtime.Serialization.SerializationException was unhandled
  Message="Type 'System.Drawing.StringFormat' in Assembly 'System.Drawing,   
Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' is not 
marked as serializable."

How do I solve this problem?