使用iTextSharp将文本添加到PDF：为什么我的文字不清晰？

Question

我正在使用iTextSharp将文本添加到PDF文件中。文本正确对齐。 问题是当我打印时，文字并不像我想要的那样清晰。 我在这做错了什么？ 我在C＃中使用WinForms。

    using iTextSharp.text;
    using iTextSharp.text.pdf;

    /// <summary>
    /// Add a page containing a single image. 
    /// Set the page size to match the image size.
    /// </summary>
    /// <param name="doc"></param>
    private void AddPageWithImage(iTextSharp.text.Document doc, String imagePath)
    {
        Bitmap bmp = new Bitmap(612, 792);
        bmp.SetResolution(72,72);
        using (Graphics graph = Graphics.FromImage(bmp))
        {
            System.Drawing.Rectangle ImageSize = new System.Drawing.Rectangle(0, 0, 612, 792);
            graph.FillRectangle(Brushes.White, ImageSize);
        }

        int totalRecords = Int32.Parse(comboBoxNumberOfGunPermits.SelectedItem.ToString());
        int y = 0;

        Graphics g = Graphics.FromImage(bmp);

        g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
        g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
        g.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;

        StringFormat format = new StringFormat();
        //format.LineAlignment = StringAlignment.Center;
        format.Alignment = StringAlignment.Center;

        StringFormat leftAlign = new StringFormat();
        //format.LineAlignment = StringAlignment.Center;
        leftAlign.Alignment = StringAlignment.Near;

        System.Drawing.Font mFont = new System.Drawing.Font("Microsoft Sans Serif", 8);

         int difference =  175;


        for (int i = 1; i <= totalRecords; i++)
        {

            g.DrawString("SOME TEXT", mFont, Brushes.Black, new RectangleF(70, 95 + y, 159, 408), format);                

            y += difference; 
        }

        g.Flush();

        string path = System.IO.Path.GetTempPath() + "/tmp.bmp";
        bmp.Save(path);
        //System.Diagnostics.Process.Start("mspaint", path);
        // Read the image file
        iTextSharp.text.Image image = iTextSharp.text.Image.GetInstance(path);

        // Set the page size to the dimensions of the image BEFORE adding a new page to the document
        // Pad the height a bit to leave room for the page header
        float imageWidth = image.Width;
        float imageHeight = image.Height;
        doc.SetMargins(0, 0, 0, 0);
        doc.SetPageSize(new iTextSharp.text.Rectangle(imageWidth, imageHeight + 100));

        doc.Add(image);
        image = null;

    }