Where to clean to remove these smudges on a Epson P900

[ymc226]

This is copy paper loaded via the rear feeder as directed for a test print after several head cleanings.  Last used about 3 months ago, loaded 17x22 paper from front and don't remember that the smudges showed up.

[dgberg]

Paper may be picking up a little moisture from humidity and curling, head strike.
Use a heavier paper if you have it with platen wide or widest.