I have a black and white laser too, a Brother. But even there do the cartridges not last long enough. I put a little tape over the 'eye' that 'reads' how full i

I have a black and white laser too, a Brother. But even there do the cartridges not last long enough. I put a little tape over the 'eye' that 'reads' how full it is, and that gives me months of additional printing.