private void Doc_PrintPage(object sender, PrintPageEventArgs e)
    {
        float x = e.MarginBounds.Left;
        float y = e.MarginBounds.Top;
        Bitmap bmp = new Bitmap(this.grbSummarySheet.Width, this.grbSummarySheet.Height);
        this.grbSummarySheet.DrawToBitmap(bmp, new Rectangle(0, 0, this.grbSummarySheet.Width, this.grbSummarySheet.Height));
        e.Graphics.DrawImage((Image)bmp, x, y);
    }

    private void btnPrint_Click(object sender, EventArgs e)
    {
        PrintDocument doc = new PrintDocument();
        doc.PrintPage += this.Doc_PrintPage;
        doc.DefaultPageSettings.PaperSize = new System.Drawing.Printing.PaperSize("PaperA3", 1200, 1180);
        PrintDialog dlgSettings = new PrintDialog();
        dlgSettings.Document = doc;
        if (dlgSettings.ShowDialog() == DialogResult.OK)
        {
            doc.Print();
        }
    }