Have you made a paper profile for the stock?? There is a setting "density uniformity" in the paper profile settings that allows you to tell the machine to put more or less toner on the page.. Try this.. it may help
Hi Olympic Printers,
Thank you for using the Support Forum. Please take a look at the Recommened Media List. The list includes the types and weights of the paper stock that can bee used in the machine. If this does not help please consider contacting your support centre for further assistance.