how to outline text based on a givent Font?

I need to outline text based on a given Font. Here is code snippet:

private void DrawText(String text, Graphics graphic)
        {
            String _text = text;

            SizeF size = new SizeF();
            Font f2 = AppropriateFont(graphic, 5, 5000,
                this.ClientSize, _text, fontGeneral, ref size);

            PointF p = new PointF(
                (this.ClientSize.Width - size.Width) / 2,
                (this.ClientSize.Height - size.Height) / 2);

            graphic.DrawString(_text, f2, Brushes.Red, p);
        }

        private Font AppropriateFont(Graphics g, float minFontSize, float maxFontSize, Size layoutSize, String s, Font f, ref SizeF extent)
        {
            if (maxFontSize == minFontSize)
                f = new Font(f.FontFamily, minFontSize, f.Style);

            extent = g.MeasureString(s, f);

            if (maxFontSize <= minFontSize)
                return f;

            float hRatio = layoutSize.Height / extent.Height;
            float wRatio = layoutSize.Width / extent.Width;
            float ratio = (hRatio < wRatio) ? hRatio : wRatio;

            float newSize = f.Size * ratio;

            if (newSize < minFontSize)
                newSize = minFontSize;
            else if (newSize > maxFontSize)
                newSize = maxFontSize;

            f = new Font(f.FontFamily, newSize, f.Style);

            extent = g.MeasureString(s, f);

            return f;
        }

I've found a way to do it with AddString but result is not the same as by using DrawString.

Any clues?

Thanks