Text resolution when printing barcode

Hi everybody, I'm evaluating RadBarcode for printing barcodes in thermal printers. My printers have a resolution of 203 dpi in both horizontal and vertical directions. I'm trying to generate an image of the barcode (EAN13) and sending to printer:

        public DrawBarcode(Point Location, Size Size, string valor): base(Location)
        {
            this.Valor = valor;
            bc = new RadBarcode();
            bc.Value = valor;
            
            var EAN13 = new Telerik.WinControls.UI.Barcode.Symbology.EAN13();
            EAN13.ShowText = true;

            bc.Symbology = EAN13;
            EAN13.Stretch = true;

            int n = 50;
            while (true)
            {
                try
                {
                    img = bc.ExportToImage(2*n, n);
                    this.size = img.Size;
                    return;
                }
                catch (Exception) { n += 10; }
            }
        }

        public override void Draw(Graphics g)
        {
            base.Draw(g);
            g.DrawImage(img, 0, 0);
        }

I have a base class for controling Drag, zoom and rotation but it is not important in this scenario. When I send the image to screen, text is rendered perfectly but when I send the image to the printer, text is not redeable. Is it any why to specify resolution in ExortToImage or any other why to change generated image resolution?