I have recently purchased a lexmark c746dn color laser printer to help with some projects.\n\nIt seams to do fine with small projects. 10 to 30 pages here or there. But the problem arises when I print projects that will over 300 pages (duplex) at one time.\n\nAs the printer "heats up" from printing, I get a gray haze/streaks on the pages and the printing quality gets worse and worse. I use 24lb premium laser paper and have decided to lower the weight to 20lb premium paper. \n\nIf I put in a new black toner it will go away for a bit but not completely, but then when I print a big project again and the haze/streaks are back. And it doesn't get better. \n\nI'm not sure if this is a toner problem, paper problem, printer problem, photoconducter problem. All my status/supplies show OK. \n\nAny suggestions or help.