Have had a couple of machines doing this. When customer prints on cardstock using the mp tray, the copies look very washed out and faded..not good at all. If you run the cardstock thru the mp tray set to plain paper the copies look o.k., but then they have jamming issues. The customers have had these machines a while and they run cardstock a lot, it seems like something changed in the machine...setting or something. We have tried new drums, dev units, transfer belts, etc. I have checked other kmc3225 machines, etc. and cardstock setting/mp tray copies look o.k. I tried to compare sim settings, but could not find anything different that worked.

I also have considered the Laser being dirty, as listed in another post, but regular copies are fine, it only seems to happen on cardstock mode. I would think if its a dirty laser then all of my copies would be light/washed out....Help!

I seem to remember something about using bond mode for problems with cardstock. Worth a try anyway.

Have you tried fresh different cardstock? Perhaps the current media has moisture problems. =^..^=

I have noticed it on 3 different customers machines so the card stock varies and i get the same problem. I have tried heavy, custom, transparency, etc. with no good results. I also played with the weight settings thru machine default mode.

Be sure to set the media to either thick or cardstock. This slows the process speed allowing more time over the transfer roller to transmit the charge through the thicker stock thus attracting more/all of the toner off the transfer belt. For printing set the media at the print driver, for copying set the media from the control panel.