The answer is print the panel of form using this code:
void PrintImage(object o, PrintPageEventArgs e)
{
Bitmap img = new Bitmap(panel3.Width, panel3.Height);
InvertZOrderOfControls(panel3.Controls);
panel3.DrawToBitmap(img, new Rectangle(new Point(), panel3.Size));
InvertZOrderOfControls(panel3.Controls);
Point p = new Point(0, 0);
e.Graphics.DrawImage(img, p);
}