None.

Here we draw some text and a box around it.

[C#]using (Bitmap bm = new Bitmap(0, 0)) {
  using (Graphics graphics = Graphics.FromImage(bm)) {
    Font font = new Font("Comic Sans MS", 72, FontStyle.Regular);
    string txt = "Man & Dog";
    SizeF sz = graphics.MeasureString(txt, font);
    bm.Resize((Size)(sz + new SizeF(40, 40)));
    RectangleF rect = new RectangleF(new PointF(20, 20), sz);
    graphics.DrawString(txt, font, new SolidBrush(Color.Fuchsia), rect.Location, StringFormat.GenericDefault);
    graphics.DrawRectangle(new Pen(Color.DarkSeaGreen, 1), rect);
    double scale = font.Size / font.FontFamily.GetEmHeight(font.Style);
    double ascent = font.FontFamily.GetCellAscent(font.Style) * scale;
    double descent = font.FontFamily.GetCellDescent(font.Style) * scale;
    double lineSpacing = font.FontFamily.GetLineSpacing(font.Style) * scale;
    double cellHeight = ascent + descent;
    double internalLeading = cellHeight - font.Size;
    double externalLeading = lineSpacing - cellHeight;
    double[] metrics = new double[] { ascent, ascent + descent, lineSpacing };
    Brush[] brushes = new Brush[] { Brushes.Red, Brushes.Green, Brushes.Blue };
    for (int i = 0; i < metrics.Length; i++) {
      double dy = metrics[i];
      Pen pen = new Pen(brushes[i], 1);
      pen.DashStyle = DashStyle.DashDotDot; // *** not rendering well
      graphics.DrawLine(pen, rect.Left, (int)(rect.Top + dy), rect.Right, (int)(rect.Top + dy));
    }
  }
  bm.Save(Server.MapPath("IG8_Graphics_MeasureString.png"));
}


IG8_Graphics_MeasureString.png