Thank you for using the Support Forum. SSince it seems to happen more on one type of paper, please take a look at this article about residual or ghost images and try the suggestions. If this does not help then it may will be the fuser as the other replier indicated. Please consider contacting your support centre for further assistance.
Sounds like you have a fuser issue.
When printing (especially on A3) my printer will perfectly print the document, apart from huge smudges and text from previous documents. Almost like previous documents are getting stamped over the current documents. I dont know how to fix this and I have printed lots of pages and its still the same.
Any ideas on how to fix this?