Take a look at your latest weight & balance report. Was the aircraft physically weighed on scales, or was it a calculated weight? You’ll probably find the report was calculated when the last modification was completed. While there’s nothing wrong with this method, overtime your aircraft gets heavier due to the compilation of negligible weight items, paint touch-up, etc. Physically weighing your aircraft provides a true weight, allowing more accurate weight and balance calculations to be made, improving the overall safety of your aircraft.