Thank you Richard.That is helpful.I just acquired the 4900 and it needed a lot of help to get it functional. Given the costs involved with using the "official" cleaning methods and my patterns of use(6 mo on, 6 mo off), I have to use other ways of handling things.QTR has been crucial as one of those ways.For me, in addition to it's monochrome RIP duties, it has multiple roles in overall maintenance. Thanks again. Duane