Brother already does this. When the printer tells you that toner is empty on a Brother laser printer, you usually have about 15-20% left. However, the printer

Brother already does this. When the printer tells you that toner is empty on a Brother laser printer, you usually have about 15-20% left. However, the printer will refuse to print anything. The solution is (no joke) to put tape over the sensor window on the cartridge, and you can get another 1000 pages or so. http://www.fixyourownprinter.com/forums/laser/39806 http://www.fixyourownprinter.com/forums/laser/39806 Proud owner of a Brother laser printer here. My guess is that this is how they can afford to sell the printers for so cheap (usually underselling HP).