Are you meaning to print to a normal printer (e.g., HP Laserjet) or an actual label printer (e.g., Zebra, Intermec, Sato, etc)?

If the latter than you normally just create the format in some label making software (e.g., Nicelabel) and then your .Net program downloads that format file to the printer and then will send the separate commands to select the desired format and fill in the appropriate fields.