printing C# window form with high quality

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C#3.0

C#

Hi,
I have created invoice in c# window form which contain multiple(90+) labels which takes values from another form in a panel and I have to print that form on a4 size paper. I am able to print the form on a4 paper but the text and the line are not clear i.e. it print text as dot-dot(faded). I am using bitmap to print the form please tell me how I can improve the quality of text on label control (If it print like pdf/doc file that will be better).
CODE is as follows :
private void printpreview_Click(object sender, EventArgs e)
{
ppd.Document = printDocument1;
ppd.ShowDialog();
}
private void printDocument1_PrintPage(object sender,System.Drawing.Printing.PrintPageEventArgs e)
{
int x = e.MarginBounds.Left / 3 + 10;
int y = e.MarginBounds.Top / 2;
Bitmap image = new Bitmap(panel1.Width, panel1.Height);
panel1.DrawToBitmap(image, new Rectangle(new Point(), panel1.Size));
Graphics g = e.Graphics;
g.PageUnit = GraphicsUnit.Display;
g.DrawImage(image, new Rectangle(new Point(x, y), panel1.Size));
}
private void button2_Click(object sender, EventArgs e)
{
pd.Document = printDocument1;
DialogResult result = pd.ShowDialog();
if (result == DialogResult.OK)
{
printDocument1.Print();
//docToPrint.Print();

}
}
The above code is working properly but quality of text on label control is very poor.